肖志斌:先进制程提速见顶 软硬件协同可追回三倍算力差距

Xiao Zhibin: AI Chips, NVIDIA, Global Supply Chain, 2nm, US-China-Japan-South Korea, Groq, Cerebr... — 月球大叔

月球大叔

随着芯片物理缩放与SRAM微缩陷入停滞,AI算力竞争的核心瓶颈已从晶体管制造转向以虚拟仿真和软硬件协同重构系统级能效。

AI-assisted summary of Xiao Zhibin: AI Chips, NVIDIA, Global Supply Chain, 2nm, US-China-Japan-South Korea, Groq, Cerebr... — original source. Check the original for full context.

Source published:

Key ideas

  • 先进制程升级的核心目标已从提升速度转向降低功耗与发热量;从 3nm 到 2nm 单芯片运行速度提升仅约 3%~5%,而 SRAM 存储单元物理缩放停滞正逼迫行业将焦点转移至系统级架构设计。 (34:18)
  • 大模型推理全流程呈现明显计算瓶颈分期:Prefill 阶段为算力密集型,Decode 阶段为极端显存带宽受限型;通过算存分离、动态调度等软硬件协同设计,软件优化可追回 2 到 3 倍的先进制程物理差距。 (40:55)
  • 英伟达的核心护城河不仅是 CUDA 生态,更在于初创企业般的极致工程执行力(如将 2:4 稀疏概念硬化入量产硅片),以及对台积电 CoWoS 先进封装与全球 HBM 产能分配的供应链绝对主导权。 (62:35)
  • ZFlow.AI 基于虚拟仿真在 8x NVIDIA B200 节点部署 DeepSeek-V3,通过仿真确定 Prefill-Decode 分离架构并注入运行时参数,在物理实测中实现峰值吞吐提升 1.5 倍、P99 尾部延迟降低 2 到 3 倍。 (94:13)
  • AI 大模型正演变为软件行业的“EDA 工具”,传统代码编写被自动化接管导致普通开发者薪资曲线面临平准化,行业超额红利将进一步向打通底层物理计算与上层业务落地的系统架构师集中。 (111:44)

Detailed notes

## Background 该视频由 YouTube 频道“月球大叔”于 2026 年 9 月 7 日发布。内容围绕访谈嘉宾肖志斌展开,基于其在浙大、UC Davis、Oracle、阿里到创办 ZFlow.AI 的二十年芯片与系统架构经验,深入探讨芯片从设计到量产、先进制程与摩尔定律瓶颈、英伟达护城河、新型 AI 芯片架构以及 AI 时代系统优化与职业选择。

## TL;DR 对话全面拆解了从 7nm 到 2nm 制程升级控功耗重于提速的工程本质,以及芯片从架构定义、EDA 验证到台积电代工的完整产业链壁垒。肖志斌深度剖析了大模型推理在 Prefill 与 Decode 阶段遭遇的内存墙困境,对比了 GPU、Groq、Cerebras 与 SambaNova 等不同硬件架构路线的取舍,并指出纯软件与系统协同调优能追回先进制程 2 到 3 倍的差距。最后,他结合创办 ZFlow.AI 打造架构级仿真平台的实践,分享了从架构师到 CEO 的转变,以及大模型作为软件业“EDA 工具”对未来工程师职业分化的深远影响。

## Atmosphere & style 整场对话呈现出高密度、极具专业纵深却又平实落地的硬核技术沙龙氛围。主持人的敏锐追问与肖志斌信手拈来的工业界实战案例形成良性互动,将晦涩的晶体管、微架构与编译调度讲得脉络清晰。听者能切身感受到一位亲历半导体风云变迁的老兵对底层工程复杂度的敬畏、对英伟达执行力与技术现实的冷静洞察,以及对 AI 原生基础设施变革的理性兴奋与前瞻思考。

## Bulletin - [34:18](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2058s) 先进制程升级的核心目标已从提升速度转向降低功耗与发热量;从 3nm 到 2nm 单芯片运行速度提升仅约 3%~5%,而 SRAM 存储单元物理缩放停滞正逼迫行业将焦点转移至系统级架构设计。 - [40:55](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2455s) 大模型推理全流程呈现明显计算瓶颈分期:Prefill 阶段为算力密集型,Decode 阶段为极端显存带宽受限型;通过算存分离、动态调度等软硬件协同设计,软件优化可追回 2 到 3 倍的先进制程物理差距。 - [01:02:35](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3755s) 英伟达的核心护城河不仅是 CUDA 生态,更在于初创企业般的极致工程执行力(如将 2:4 稀疏概念硬化入量产硅片),以及对台积电 CoWoS 先进封装与全球 HBM 产能分配的供应链绝对主导权。 - [01:34:13](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5653s) ZFlow.AI 基于虚拟仿真在 8x NVIDIA B200 节点部署 DeepSeek-V3,通过仿真确定 Prefill-Decode 分离架构并注入运行时参数,在物理实测中实现峰值吞吐提升 1.5 倍、P99 尾部延迟降低 2 到 3 倍。 - [01:51:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6704s) AI 大模型正演变为软件行业的“EDA 工具”,传统代码编写被自动化接管导致普通开发者薪资曲线面临平准化,行业超额红利将进一步向打通底层物理计算与上层业务落地的系统架构师集中。

## Key takeaways - [33:05](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1985s) 先进制程纳米标号已与物理栅极长度脱钩,3nm 和 2nm 本质上是技术代际营销代号,升级收益主要体现为降低功耗与提升机柜算力密度,而非单芯片绝对计算速度的大幅增加。 - [13:10](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=790s) 芯片设计具有极高试错成本:从架构定义到量产通常耗时 3 至 5 年,单次流片失败损失数千万至上亿美元并错失市场窗口期,导致研发团队中验证人员编制通常是设计人员的 2 到 3 倍。 - [28:59](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1739s) 全球半导体产业链没有任何单一国家能自给自足:美国垄断底层 IP 与 EDA 软件,荷兰垄断先进光刻机,日本把控关键制造设备与特种化学材料,中国台湾主导先进制程代工,韩国主导高端 HBM 内存制造。 - [30:30](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1830s) 开源指令集 RISC-V 具备无历史兼容包袱与高度模块化扩展的优势,已被英伟达等主流大厂广泛集成于旗舰芯片内部作为核心微控制器与专用加速扩展底座。 - [39:21](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2361s) SRAM 缩放停滞危机直接冲击纯片上存储架构:从 7nm 到 3nm 节点 SRAM 单元面积缩减停滞,使得极度依赖大容量片上 SRAM 的 Groq 和 Cerebras 面临严重的硅片面积配比与芯片级联经济性挑战。 - [40:55](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2455s) 大模型推理的 Prefill 与 Decode 阶段存在本质架构冲突:Prefill 属于算力密集型,Decode 自回归逐字生成则是内存带宽严重受限型,针对超大模型的推理优化核心在于实现通信与计算的高效重叠。 - [59:13](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3553s) 软硬件协同设计能弥补 2 到 3 倍的物理制程硬件差距,通过算存分离、低精度量化、投机解码与集群编排,可将数据中心当前普遍仅 30%~50% 的真实硬件利用率翻倍提升至 80%~90%。 - [01:02:35](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3755s) 英伟达兼备技术执行力与供应链壁垒:当竞品停留在学术探讨时,英伟达已将稀疏计算硬化入 Tensor Core,并果断收购 Mellanox 补齐高速集群网络,锁定了台积电 CoWoS 与 HBM 的全球核心配额。 - [01:05:43](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3943s) AI 基础设施演进的终极目标是将 Token 边际成本降到像自来水一样便宜,但发电厂建设、电网扩容及晶圆制造等物理世界长达数年的扩产周期构成了严重的物理扩张枷锁。 - [01:17:10](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4630s) Sun Microsystems 与 SPARC 处理器的衰落教训证明,独立私有指令集与闭源操作系统生态若无法抵御标准化生态的冲击,最终难逃被通用开放标准(x86 与开源 Linux)全面取代的宿命。 - [01:19:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4784s) 开源是大国与企业竞争的多维战略武器:头部领先者难以通过开源回收数十亿美元的算力支出,而后发追赶者则可将开源作为瓦解垄断、迅速构筑开发者生态并实现战略反超的杠杆。 - [01:34:13](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5653s) AI 基础设施需要中立的架构级虚拟仿真平台:通过端到端模拟异构硬件、分布式网络拓扑与动态调度,可在物理机器部署前精准预测并输出最优 Prefill-Decode 分离拓扑与运行时参数。 - [01:43:46](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6226s) 类比早期的 VMware 虚拟化层与数据库查询优化器,AI 基础设施软件团队必须深入复杂异构系统的微架构层面,成为非英伟达生态及开源社区的“外包架构团队”以打破巨头挤压。 - [01:54:03](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6843s) AI 时代的开发者必须建立全栈“架构师思维”:代码编写逐步被基座大模型接管并“EDA 化”,只有具备从底层物理计算硬件到顶层业务模型全局拆解能力的工程师才能维持极高的技术溢价。

## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=0s) Teaser and Introduction: From Transistors to Systems

The episode opens with rapid-fire insights highlighting the core paradoxes and real-world friction of the modern semiconductor landscape. While the public often assumes that shrinking process nodes from 7nm to 5nm, 3nm, or 2nm is all about raw speed, the primary engineering objective is actually controlling power consumption. Compounding this, physical constraints such as the annual delivery volume of advanced lithography equipment create strict industry bottlenecks, while the stakes of physical chip design remain punishingly high: a single failed tape-out can instantly wipe out hundreds of millions of dollars and one to two years of development. Against this backdrop, the next wave of transformative hardware ventures will likely emerge as "AI-native chip design firms."

Host Uncle Yueqiu, who is interviewing 100 notable figures across Silicon Valley, introduces guest Xiao Zhibing—a veteran chip architect whose career spans over two decades. Xiao entered Zhejiang University in 1999, earned his doctorate at the University of California, Davis (UC Davis), and has spent his professional life designing processors at the highest levels of industry. Uncle Yueqiu observes that Xiao’s path—progressing from embedding accelerators into CPUs, to building dedicated AI processors and sparse computing silicon, to now leading a system optimization startup that avoids manufacturing chips altogether—raises a vital question: has the decisive battlefield for AI performance permanently shifted away from transistor scaling and into software and system-level co-design? Xiao confirms this immediately, noting that the true performance bottleneck has migrated from discrete chip design to heterogeneous, system-level architecture.

[01:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=104s) Foundations in Architecture: From Yale Patt's Lecture to Streaming DSPs

Xiao explains that across his entire career, his core discipline has remained unchanged: hardware-software co-design and computer architecture focused on making systems compute as efficiently as possible. Originally an electrical engineering undergraduate at Zhejiang University, his trajectory shifted when he attended a summer course on computer organization and architecture taught by Professor Yale Patt—the renowned pioneer behind modern CPU branch prediction. Inspired by Patt's teachings, Xiao fell in love with architecture and began working on single-core digital signal processors (DSPs) around 2002 and 2003. At the time, China was funding domestic microprocessor initiatives through frameworks like the 863 Program, offering Xiao a rare chance as a student to participate in the forward design of large-scale silicon. His graduate work centered on extending the instruction set of traditional MIPS architectures with dedicated multimedia instructions, tailored specifically to handle real-time MPEG audio and video encoding for VCD players.

Transitioning to his doctoral studies at UC Davis, Xiao moved from single-core architectures to multi-core DSP arrays designed for stream computing. The objective was solving high-throughput communication pipelines, video encoding, and large-scale query sorting through on-chip dataflow principles. Rather than constantly shuttling data back and forth to off-chip memory, computation was structured so that data flowed directly across a network of interconnected DSP cores, each equipped with minimal instruction and data memory alongside independent dynamic voltage and frequency scaling (DVFS). This research fundamentally mirrored the modern dataflow architectures that power today's dedicated AI processors.

```mermaid flowchart TD accTitle: Evolution of Xiao Zhibing's Architectural Work accDescr: A progressive diagram showing Xiao's trajectory from early single-core DSPs to modern AI system-level simulation.

subgraph Academic["Academic Research (ZJU & UC Davis)"] A["ZJU (2002-2003)<br/>MIPS Single-Core DSP<br/>MPEG/VCD Multimedia ISA"] B["UC Davis (PhD)<br/>Multi-Core Stream Computing<br/>On-Chip Dataflow & DVFS"] A --> B end

subgraph Industry["Enterprise & Hyperscale Silicon"] C["Oracle (SPARC)<br/>In-Memory DB Coprocessor<br/>Hardened TPC-H Operators"] D["Alibaba & Startups<br/>Hanguang 800 NPU<br/>Sparse AI Silicon"] B --> C C --> D end

subgraph Modern["System Optimization"] E["ZFlow.AI<br/>Unified Virtual Simulation<br/>Compiler & Runtime Scheduling"] D --> E end ```

- **Early ISA Extension:** Implemented dedicated multimedia instructions on MIPS to accelerate VCD-era MPEG encoding. - **Dataflow Parallels:** Doctoral research anticipated modern AI spatial accelerators by focusing on keeping data on-chip between multi-core DSP nodes to circumvent memory bus bottlenecks.

[05:49](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=349s) Enterprise Silicon at Oracle and Alibaba: Hardening Database and AI Workloads

Xiao spent five to six years at Oracle working on the SPARC enterprise server processor line. Following Oracle’s acquisition of Sun Microsystems, the team faced the challenge of innovating on architectures that, together with the Solaris operating system, had historically anchored mission-critical enterprise environments requiring non-stop uptime for years without rebooting. To serve Oracle's core database workloads, the hardware team designed dedicated coprocessor acceleration units embedded directly on the SPARC die. By sharing full memory bandwidth with the host CPU, these accelerators could saturate memory bandwidth to power in-memory database queries. The team hardened the 22 relational queries of the industry-standard TPC-H benchmark directly into hardware, designing a custom instruction set and runtime integrated seamlessly into Oracle’s database query optimizer.

Following his tenure at Oracle, Xiao transitioned to Alibaba, where he contributed to the development of the Hanguang 800 (含光800), Alibaba's flagship first-generation AI inference chip. He subsequently co-founded a startup dedicated to sparse AI processors. Across both database hardware acceleration and dedicated neural processing units, the trend remained consistent: specialized workloads demanded purpose-built execution pipelines tightly coupled with specialized software runtimes.

- **SPARC Database Accelerator:** Offloaded in-memory database operations directly onto the CPU die to fully saturate available memory bandwidth. - **TPC-H Acceleration:** Translated all 22 TPC-H relational benchmark operations into custom hardware functional units, complete with dedicated instructions. - **AI NPU Experience:** Direct architectural leadership on Alibaba's Hanguang 800 and subsequent sparse AI accelerators.

[07:49](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=469s) The Shift to ZFlow.AI: Tackling Post-Moore's Law Bottlenecks

As Moore's Law visibly decelerated, Xiao recognized that extracting substantial performance or energy efficiency gains purely at the single-chip silicon level was hitting diminishing returns. The true crisis had shifted upstream to the system, cluster, and software levels. If dozens of semiconductor startups were already fighting over single-chip execution units, the highest-leverage endeavor was addressing the software-to-hardware mismatch across large AI clusters. This realization led Xiao to establish ZFlow.AI, an infrastructure optimization venture that replaces costly trial-and-error hardware deployment with architectural simulation and automated profiling.

ZFlow.AI unifies model compilation, runtime scheduling, and distributed system simulation into a cohesive platform. Because large-scale GPU clusters are exceedingly expensive and scarce, systems engineers rarely have access to physical clusters to test alternative topologies, interconnects, or runtime configurations. Xiao's simulation platform allows engineers to evaluate how different models behave on specific architectures—determining precisely which neural network runs most economically on which hardware, whether that hardware currently exists or is still on the drawing board. When Uncle Yueqiu notes that this makes ZFlow.AI an ideal launchpad to uncover ideal architectures, Xiao agrees: if simulation proves that a specific workload has stabilized and converged—such as vision tasks for robotic vacuums or parking lot monitors—the company could readily design or incubate dedicated silicon to accelerate that fixed workload.

- **Unified Simulation Stack:** Integrates deep learning model compilation, runtime scheduling, and cluster-level hardware simulation. - **Economic Hardware-Model Matching:** Evaluates the dollar and energy cost of running frontier models on hypothetical or heterogeneous hardware setups before making hardware purchase or tape-out commitments. - **Potential for Custom Silicon:** Leaves the door open to spinning out dedicated ASICs whenever customer algorithmic tasks reach architectural convergence.

[11:50](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=710s) 激进架构与 Tenstorrent:固化模型与金属层重调

在讨论 AI 推理芯片的架构分歧时,肖志斌提到了加拿大明星芯片公司 Tenstorrent。这家公司不仅拥有极为知名的联合创始人,如今的掌舵人更是硅谷传奇芯片架构师 Jim Keller。他们的技术路线非常激进,但依然能持续吸引资本青睐,核心原因在于它押注了一个趋势:对于某些垂直或特定任务,AI 模型结构正在逐渐收敛、趋于固化。从经济账来算,把固定的计算逻辑直接通过硬件“硬连线”(hard-wired)烧进芯片,往往能带来极高的效率和性价比。

不过,Tenstorrent 的设计并非完全不可逆的纯死硬连线,而是在架构灵活性与专用性之间做出了精巧折中。他们将芯片的灵活性保留在金属层(Metal Layers)上。这意味着芯片具备一定程度的“可编程性”,但如果下游算法发生重大调整,需要更改硬件逻辑,用户并非通过纯软件烧录,而是要把晶圆送回代工厂重新流片制造最顶层的几层金属走线(Metal Fix / Re-spin)。相比完整重做整颗芯片的全掩膜流片(Full Re-spin),这种做法成本低廉得多,但在软件开发者看来依然是一件不可思议的“硬件级操作”。

- Tenstorrent 现任 CEO 为前 AMD、苹果、特斯拉顶级芯片架构师 Jim Keller。 - 架构权衡点:利用模型固化趋势换取最高能效,通过重新制作金属层实现比完整重新流片成本低得多的硬件更新。

---

[13:10](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=790s) 一颗芯片的诞生:从市场需求到架构与微架构设计

针对主持人“完全不懂芯片的人如何理解芯片从设计到量产”的追问,肖志斌拆解了芯片漫长而精密的研发链条。过去传统 CPU 的研发周期极其冗长,光是设计就需要两到三年,加上流片、封装测试、软硬件系统协同,通常需要三到五年才能正式推向市场;即便当今节奏最快的英伟达,一年看似推出数款新品,实际也是多个团队重叠推进、每颗芯片至少经历两三年研发的结果。造芯片就像建大楼,第一步永远是市场需求驱动(Market-driven),先决定芯片的定位:是专用的编解码芯片、特定协议的通信芯片(如 Wi-Fi),还是通用的 CPU、GPU。

以大型视频流媒体平台为例,全球数十亿台手机拍摄的视频格式五花八门,云端必须通过定制转码芯片将其统合为标准格式存储,并在下发给不同设备时,根据终端性能和网络分辨率动态二次转码。如果全靠通用 CPU 来处理这种计算,服务器成本将极其高昂,因此云厂商(CSP/Hyperscaler)会明确提出定制专用编解码芯片的诉求。需求确定后,芯片架构师(Architect)入场,核心任务是在 PPA(Power 功耗、Performance 性能、Area 面积)以及 Cost(成本)之间走钢丝,同时完成竞品调研,确保设计在两三年后推向市场时不至于落伍。架构师输出系统级 Spec(规格说明书)后,微架构师(Micro-architect)接棒,将指令级或高层模块转化为可实现的具体硬件结构。例如一个 FFT 硬件加速模块存在无数种实现方式,微架构师需要结合约束完成取舍,并亲自编写 RTL(Register-Transfer Level,硬件描述语言)代码,完成芯片的底层硬件逻辑搭建。

```mermaid flowchart TD accTitle: Chip Design and Production Flow accDescr: High-level overview of the semiconductor development lifecycle from market requirements to tape-out and mass production.

subgraph Phase1["前端需求与架构设计"] A["市场需求确认<br/>(CSP/专用场景驱动)"] --> B["架构师定义 Spec<br/>(平衡 PPA 与成本)"] B --> C["微架构实现与 RTL 编码<br/>(硬件描述语言)"] end

subgraph Phase2["验证与物理实现"] C --> D["全方位多级验证<br/>(功能/形式/仿真/Palladium)"] D --> E["后端物理实现<br/>(综合、布局布线、时钟、供电)"] end

subgraph Phase3["制造、封测与量产"] E --> F["晶圆代工制造<br/>(TSMC/中芯国际,耗时3-4个月)"] F --> G["晶圆缺陷测试与切割 Die"] G --> H["封装测试与系统板级验证"] H --> I["客户送样测试与最终量产"] end ```

---

[16:49](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1009s) 严苛的芯片验证:黄仁勋“孤注一掷”买模拟器的故事

在芯片设计中,验证工程师(Verification Engineer)的地位极其关键。在 AI 浪潮爆发之前,传统芯片设计公司内部的研发配比通常是“1 名设计工程师对应 2 到 3 名验证工程师”,验证团队往往占据绝大部分人力。验证流程涵盖功能验证、形式验证(Formal Verification)、时序验证、物理验证等,流片前还要通过大型 FPGA 阵列或购买 Cadence 昂贵的专业硬件仿真加速器(如 Palladium)进行高保真仿真。原因十分残酷:芯片一次流片(Tape-out)动辄耗资几千万甚至数亿美元,一旦失败不仅资金归零,更会白白浪费一到两年的市场窗口期。

肖志斌特别分享了英伟达创始人黄仁勋创业早期的生死抉择:当年英伟达资金极度紧绷、濒临破产边缘,黄仁勋却力排众议,把公司账上最后的钱砸去买了一台昂贵的硬件仿真器(Emulator)。正是靠这台设备在流片前完成了对 GPU 的严密验证,英伟达才得以一举成功翻盘。在早期的芯片行业,由于验证工具匮乏,芯片必须反复流片好几次才能成功;而现代工业级验证体系与仿真工具的成熟,使得芯片“首版流片即成功”(First-pass Silicon Success)成为常态,最多只需做微小的金属层修正(Metal Fix)。

- 芯片研发人员配比:传统阶段 1 名设计工程师通常需要配备 2~3 名验证工程师。 - 流片成本与风险:先进工艺流片开销数千万至上亿美元,任何细微逻辑 Bug 都会导致一年以上时间成本与巨额资本彻底打水漂。 - 典故:黄仁勋在创业生死存亡关头花光最后的资金购买仿真器,确保 GPU 首版验证成功,奠定了英伟达的生机。

---

[17:45](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1065s) 从晶圆掩膜到系统送样:物理实现与漫长制造闭环

当 RTL 代码验证无误后,芯片进入后端物理实现阶段:通过综合工具生成门级网表,进行物理布局布线(Place and Route)、时钟树综合、电源完整性分析,并与下游系统整机厂商联合完成供电与封装设计。全部版图准备完毕后,数据被交付给台积电(TSMC)或中芯国际等晶圆代工厂,这一步通常需要 3 到 4 个月的制造周期。

在这三四个月的制造期内,代工厂根据输入的版图制作光掩膜(Mask),在硅片上一层一层地完成光刻、刻蚀与离子注入,芯片的复杂程度直接体现在堆叠的印刷层数上,现代先进制程往往需要数十套甚至上百套光掩膜。晶圆出厂后,首先要送往晶圆测试厂(Wafer Sort)逐一排查硅片物理缺陷,随后切割成单颗晶圆裸片(Die)并由代工厂担保基础良率(Yield)。切割后的裸片送交封测厂进行封装保护并引出引脚。最后,封装好的芯片被焊接在系统开发板上,进行极端实验室条件测试与板级功能验证,并在向客户送样(Sampling)通过后,才正式迈入大规模量产。面对主持人惊叹芯片制造之复杂脆弱,肖志斌直言:从架构到硅片良率、封装散热(Thermal Management)、全球供应链,再到底层基础软件的同步适配,整条链路容错率极低,任何环节掉链子都会引发灾难性的延期。

---

[21:20](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1280s) AI 改变芯片行业:从单点工具到“AI 原生”芯片公司

谈及当前硅谷正在兴起的使用 AI Agent 介入芯片设计与验证的初创企业,肖志斌表示业内许多核心项目均由他的朋友创办,这是整个半导体界不可逆转的技术大趋势。目前 AI 在芯片领域的落地主要集中在两大板块: 1. **芯片验证**:因为验证的本质逻辑与软件编写高度类似,输入输出边界明确,且具备极强的可模拟环境(Simulated Environment)用于闭环反馈校验,因此类似 Coding Agent 的验证 Agent 正在快速落地; 2. **后端物理设计**:像 EDA 巨头 Synopsys 与 Cadence,早已将 AI 算法深度整合进布线优化与平面规划(Floorplanning)中。

然而,AI 在芯片研发中仍有两个巨大的“未解命题”。其一是**前端架构决策**:目前行业极度缺乏能帮工程师决定“到底造一颗什么芯片、采用何种微架构、怎样定义边界”的架构级 AI 工具,核心构想依然重度依赖顶级架构师的经验直觉。其二是**组织与流程包袱**:传统芯片大厂内部拥有根深蒂固的既有工作流(Workflows),资深工程师排斥破坏现有流程去引入 Agent,大多数巨头目前仅把 AI 当作边缘“补丁工具”。肖志斌断言:真正能把 AI 生产力发挥到极致的,绝不是在传统体系里修修补补的公司,而将是一家彻底重塑端到端架构、设计、验证与物理实现的“AI 原生”(AI-Native)芯片公司。

[23:34](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1414s) AI-Native Chip Organizations, Custom Video ASICs, and the Modern Role of FPGAs

Xiao Zhibin expresses an open-minded conviction about the future of semiconductors: he firmly believes that the most transformative chip companies of tomorrow will be entirely AI-native organizations. When the host marvels at his optimism after witnessing decades of industry cycles, Xiao explains that existing semiconductor incumbents are constrained by established corporate inertia and legacy engineering practices. As the host notes, "it's hard to disrupt one's own business," meaning genuine architectural leaps may require ground-up AI-first companies to survive and outpace incumbents. Inspired by this perspective, the host remarks on the vast career opportunities opening up for students entering the field, before pivoting to custom application-specific hardware. Drawing on his own background in video network streaming, the host highlights how hyperscalers like YouTube design in-house custom ASICs to offload decoding and encoding tasks, saving astronomical annual operational costs—an investment Xiao affirms makes complete sense from a Total Cost of Ownership (TCO) standpoint.

The conversation turns to FPGAs (Field-Programmable Gate Arrays), which the host recalls being ubiquitous during his PhD research but seemingly less visible in recent AI headlines. Xiao clarifies that while FPGAs are no longer competitive for mainstream, high-throughput AI data center inference compared to dedicated accelerators, they remain vital across several specialized domains:

- **Chip Emulation and Verification**: Hardware engineers rely on FPGAs to prototype and validate complex logic circuits before committing designs to expensive silicon tape-outs. - **Dynamic Interconnects and Protocols**: Where chip-to-chip interfaces or communication protocols are undergoing rapid iteration, FPGAs offer reconfigurability that fixed ASICs cannot match. - **Fragmented Edge Workloads**: In niche applications where workloads are not yet standardized enough to justify full ASIC production runs, FPGAs provide a programmable bridge.

---

[25:50](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1550s) Global Chip Division of Labor: Foundries, IP, and the EDA Oligopoly

The host raises a common geopolitical narrative: that the United States monopolizes chip architecture and design through giants like NVIDIA and Apple while outsourcing physical fabrication entirely overseas to TSMC. Xiao agrees with this characterization in broad strokes, but emphasizes that the foundational pillar of American semiconductor supremacy extends beyond high-level architecture into fundamental Intellectual Property (IP) and Electronic Design Automation (EDA) software. Instruction set architectures, whether historical x86 licenses or the open RISC-V standard conceived at UC Berkeley, trace their lineages to the US, while ARM provides crucial licensed architectural IP from the UK.

```mermaid flowchart TD accTitle: Semiconductor Global Supply Chain and Ecosystem accDescr: Interdependent global links spanning IP, EDA, manufacturing, and equipment across key regions.

subgraph Design["Upstream Design & Tooling"] IP["Core IP & Architectures<br/>(x86, ARM, RISC-V)"] EDA["EDA Tool Suites<br/>(Synopsys, Cadence, Mentor)"] end

subgraph Fab["Fabrication & Processing"] Foundry["Advanced Foundries<br/>(TSMC, SMIC, Samsung)"] Equip["Specialized Equipment & Materials<br/>(ASML Lithography, Tokyo Electron)"] end

Design --> Foundry Equip --> Foundry ```

When asked to unpack what EDA actually stands for, Xiao explains that Electronic Design Automation serves as the indispensable software platform powering every stage of microelectronic engineering: "without these three, basically no one could design AI or chips." Just as scientific computing leans on MATLAB, chip design requires sophisticated software suites across each sub-discipline: - **System Architecture**: Tools like Synopsys Platform Architect model early hardware performance trade-offs. - **Logic Synthesis**: Cadence Genus compiles Register-Transfer Level (RTL) code directly into gate-level netlists. - **Simulation and Verification**: Simulators such as Synopsys VCS verify RTL integrity through extensive functional testing. - **Physical Design (Place & Route)**: Dedicated tools translate netlists into physical transistor placements and routing layouts, coupled with static timing and formal verification engines. - **Advanced Packaging**: Specialized EDA engines handle package design, signal integrity, and multi-die 2.5D/3D interconnects.

Xiao points out that EDA software carries immense pricing power and represents decades of aggressive mergers and acquisitions that absorbed hundreds of niche startups into the "Big Three"—Synopsys, Cadence, and Mentor Graphics (Siemens EDA). Furthermore, their backend physical design tools must be co-developed hand-in-hand with leading foundries at every fabrication node, creating an almost insurmountable barrier to entry built on deep capital reserves and shared process manufacturing secrets.

---

[28:59](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1739s) The Global Semiconductor Supply Chain and Choke Points

Xiao outlines the intricate, geographically distributed nature of the semiconductor value chain, dispelling the notion that any single country operates in total self-sufficiency. The manufacturing segment ("foundry") encompasses both pure-play logic foundries like TSMC and memory manufacturers fabricating DRAM and NAND flash. While the US and China feature the broadest overall coverage across various supply chain links—China hosting players like SMIC for foundry, YMTC for NAND, DRAM producers, and domestic FPGA startups—the global ecosystem relies on critical single-point choke points scattered across allied nations:

| Region / Country | Key Domain | Leading Entities / Roles | |:--- |:--- |:--- | | **United States** | Core EDA tools, leading logic architecture & IP, advanced chip design | Synopsys, Cadence, Mentor Graphics; NVIDIA, Apple; RISC-V roots | | **United Kingdom** | Architecture & processor core IP licensing | Arm | | **Netherlands** | Extreme Ultraviolet (EUV) and DUV lithography systems | ASML | | **Japan** | Semiconductor fabrication equipment, photoresists, specialty chemical materials | Tokyo Electron, specialized chemical suppliers | | **Taiwan & South Korea** | Advanced logic foundries, high-bandwidth memory (HBM), DRAM | TSMC, Samsung Electronics, SK Hynix | | **China** | Full-spectrum domestic chain, logic foundries, NAND flash memory | SMIC, YMTC, domestic RISC-V and FPGA ventures |

Xiao emphasizes that without ASML's lithography systems from Europe or Japan's specialty chemical materials and Tokyo Electron processing tools, advanced manufacturing grinds to a halt worldwide.

---

[30:30](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1830s) RISC-V: Breaking Free from Legacy Architectures through Open Source

The host prompts Xiao on the meteoric rise of RISC-V, noting UC Berkeley's historic pedigree in computer architecture and open-source software. Recalling past conversations with the creators of RISC-V, Xiao details the original motivation behind the project: researchers wanted to explore innovative processor microarchitectures, but proprietary commercial architectures—primarily Arm and x86—were prohibitively expensive to license and carried restrictive terms that prevented open academic collaboration and experimentation.

To overcome these barriers, the Berkeley team created a clean-slate, open-source Instruction Set Architecture (ISA). Designing an ISA from scratch offered immense architectural advantages: - **Zero Legacy Baggage**: Designers were free from backwards-compatibility compromises accumulated over decades of legacy computing workloads. - **Modular Scalability**: The base integer instruction set can be easily extended with customized vector, floating-point, or AI acceleration modules. - **Pervasive Industry Adoption**: Beyond academia, major hardware vendors now integrate RISC-V cores as embedded management engines and auxiliary controllers—including widespread use inside NVIDIA's own flagship GPUs.

The host and Xiao reflect on the vibrant RISC-V community, coordinated through the RISC-V Summit and international consortiums. Companies like SiFive in the US, Andes Technology in Taiwan, and numerous domestic startups spun out by Alibaba ecosystem alumni have popularized the architecture. Xiao notes that the global semiconductor engineering community remains surprisingly tight-knit: despite geopolitical friction between the US and China, technical collaboration and cross-border cooperation within open-source alliances remain active, with industry conferences frequently feeling like reunions of former university classmates and colleagues.

---

[33:05](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1985s) What "Nanometers" Really Mean: From Physical Gate Length to Marketing Metric

Addressing the relentless media buzz surrounding 7nm, 5nm, 3nm, and upcoming 2nm production nodes, the host asks what these measurements actually quantify in physical silicon. Xiao reveals a fundamental truth about modern semiconductor nomenclature: prior to roughly the 65-nanometer node, a node's numerical value directly corresponded to a tangible physical dimension inside the transistor—specifically the **gate length** controlling current flow between the source and drain terminals of standard planar transistors.

However, once the industry pushed beyond 65nm, physical scaling hit severe quantum leakage barriers, causing the term "nanometer" to decouple from physical gate dimensions. Today, node names like 3nm or 2nm are effectively "marketing terms" that designate a holistic technological generation rather than any individual physical metric. These modern generational labels encapsulate complex architectural shifts, such as moving from planar transistors to 3D FinFET structures (and onward to Gate-All-Around / nanosheet architectures), along with tightening contacted poly pitch and metal pitch interconnections to achieve higher functional transistor density across the die.

[34:18](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2058s) 芯片制程的真相:纳米代际的核心不是提速,而是降低功耗

芯片在硅片之上的金属层互连(Copper interconnects / Metal interconnects)中,最底层金属线的线宽与间距被称为 Metal Pitch。像 Metal Pitch、标准单元(Standard Cell,如与门、或门等门级电路的基础逻辑单元尺寸),以及片上存储器 SRAM 的密度等综合技术参数,共同定义了一代工艺制程。芯片制造厂商所宣称的 7nm、5nm 乃至 12nm,在物理层面上并不对应某一个单一的真实尺寸,且台积电(TSMC)、三星(Samsung)和英特尔(Intel)各自标称的 7nm 彼此间缺乏可比性。业内实际横向对比的是标准单元的逻辑单元面积、SRAM 存储密度,以及特定设计方案下的 PPA(Power, Performance, Area,功耗、性能、面积)表现。

大众普遍存在一个反直觉的误解,认为制程从 7nm 推进到 5nm 或 3nm,首要目的是让芯片跑得更快。实际上,先进制程代际升级的核心在于**降低功耗**。在维持相同性能的前提下,先进制程可以将功耗大幅缩减;相比于速度提升,功耗改善的收益要巨大得多。以台积电从 N3(3nm)升级到 N2(2nm)为例,功耗通常能下降 10% 到 15%,而计算速度的提升可能仅有 3% 到 5% 左右。功耗下降意味着发热量随之锐减,同一个数据中心机柜内便能容纳更多的计算节点,从而实现更高的算力密度(Computing Density)。

过去在 7nm 或 5nm 之前,芯片设计长期遵循登纳德缩放定律(Dennard Scaling)——随着晶体管物理面积缩小,工作电压也会同步降低。但当制程逼近极限时,受限于晶体管开关的基础物理特性,阈值电压无法再无底线地下调。芯片的总功耗主要由两部分构成: - **静态功耗(Static Power Consumption)**:电路处于通或断的稳定状态下产生的漏电流功耗。在 16nm、12nm 及更早制程中,动态功耗占绝对主导;但到了纳米极限节点,漏电流效应显著恶化,静态功耗越来越大。 - **动态功耗(Dynamic Power Consumption)**:逻辑门状态翻转切换时消耗的能量。

由于在纳米极限制程中降低发热和功耗是第一要务,2nm 芯片相对于 7nm 芯片能够让单机柜爆发更强算力,减少由于设备分散而产生的远距离数据搬运开销。

---

[39:21](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2361s) SRAM 缩放停滞引发的架构危机:Groq 与 Cerebras 面临的瓶颈

在现代 AI 芯片的硅片面积划分中,大致呈现“一半是逻辑运算单元,一半是片上高速存储 SRAM”的格局。然而业界正在遭遇一个多数人尚未察觉的物理硬伤:**SRAM 的物理微缩(Scaling)在 7nm 到 3nm 节点之间几乎已经完全停滞**。尽管计算逻辑单元仍能随着工艺节点不断缩小尺寸,但 SRAM 单个单元的面积(Cell Size)却无法进一步等比例压缩。

这一物理现实对不同的芯片设计路线产生了深远的震动: - **对算力密集型任务**:逻辑单元继续微缩依然能够带来晶体管集成度红利。 - **对存储受限(Memory-Bound)架构**:对于极其依赖超大规模片上 SRAM 的芯片厂商(如 Groq 和 Cerebras),由于片上存储单元无法继续缩减,其现有的芯片架构设计哲学不得不发生剧烈转变。这类芯片必须转向寻求新的工程出路,例如调整计算逻辑与存储的芯片面积配比,或是依赖先进的 3D 堆叠封装(3D Stacking)技术来维系容量优势。

```mermaid flowchart TD accTitle: 芯片先进制程缩放分化机制 accDescr: 展示制程演进下逻辑电路持续缩小与SRAM微缩停滞对AI芯片架构的影响

subgraph Scaling["工艺制程演进 (7nm -> 3nm -> 2nm)"] L["逻辑单元 (Logic)"] -->|持续微缩缩小| L_Benefit["算力密度持续提升 (Compute-Bound 受益)"] S["片上存储 (SRAM)"] -->|尺寸几乎停滞不缩| S_Limit["面积占比膨胀 / 容量提升受阻"] end

subgraph Impact["芯片架构路线的分化抉择"] S_Limit --> Groq["超依赖片上 SRAM 阵列的架构<br/>(Groq, Cerebras)"] Groq --> Workaround["倒逼架构设计变革:<br/>1. 重新调整计算/存储面积比<br/>2. 依赖 3D 芯片堆叠封装"] end ```

---

[40:55](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2455s) 拆解数据中心大模型推理全链路:从 Prompt、调度到 Prefill 与 Decode

当用户在客户端发出一段 Prompt 到数据中心最终获得流式生成的全过程,底层的软硬件交互经历了一套复杂的流水线:

```mermaid flowchart LR accTitle: 大模型数据中心推理生命周期 accDescr: 展示用户 Prompt 从网关进入调度器,经过 Prefill 与 Decode 阶段最终生成 Token 的全流程

subgraph Ingestion["接入与调度"] A["用户 Prompt 输入"] --> B["网关与调度器 (Scheduler)"] B --> C["上下文组织 & RAG 历史检索<br/>(Disk/DB/GPU Memory)"] end

subgraph Prefill["Prefill 首字填充阶段"] C --> D["推理 Runtime 运行时"] D --> E["Batching 并批处理"] E --> F["计算密集型运算<br/>并行处理 Context 并生成 KV Cache"] end

subgraph Decode["Decode 自回归解码阶段"] F --> G["内存带宽受限运算 (Memory-Bound)<br/>逐个 Token 串行生成"] G --> H["写回新 KV Cache / 循环迭代"] H -->|流式返回 Token| A end ```

1. **接入与调度(Gateway & Scheduler)**:用户的 Prompt 经由本地设备发往网络,到达数据中心网关后首先进入服务端的中央调度器(Scheduler)。调度器依据集群中现有的 GPU 负载与可用算力资源进行排队,决定将该请求路由至具体的某台服务器及 GPU 实例。 2. **上下文组织与 RAG 检索**:若包含对话历史或需要检索增强,系统会执行 RAG 流程,从底层磁盘、数据库或直接从 GPU 显存(若是连续对话会话)中调取上下文,拼装成完整的输入 Prompt。 3. **Prefill(预填充阶段)**:驻守在服务器底层的推理引擎(Runtime)接收到任务后,负责从内存或存储将模型载入 GPU,并将多个并发用户的 Context 进行合流批处理(Batching)。 - **特性**:Prompt 中现有的 Token 之间没有前后时序依赖,可以实现高度并行化计算。 - **瓶颈**:属于典型的**算力密集型(Compute-Bound)**,直接由 GPU 的原始算力峰值(TFLOPS)决定。此阶段运算完成后,会产生中间注意力键值对——**KV Cache**,并驻留在 GPU 显存或外部 Flash/SSD 存储中。 4. **Decode(自回归解码阶段)**:大模型生成答案是一个 Token 接着一个 Token 输出的逐字过程。 - **特性**:属于极其棘手的**内存带宽受限型(Memory-Bound)**任务。为了计算并输出哪怕仅仅一个新 Token,系统必须把整个模型的权重参数以及此前累积的全部 KV Cache 从显存重新完整遍历加载一遍。 - **数据搬运风暴**:每生成一个新 Token,KV Cache 矩阵就会新增一列并写回存储;生成下一个 Token 时又必须把增量后的 KV Cache 和模型权重完整重读一遍,导致恐怖的数据搬迁(Data Movement)与显存带宽压力。 5. **分布式互连通信与 Pipeline 调优**:面对如 DeepSeek-V3(6710 亿参数)、Qwen-2.5(720 亿参数)等超大模型,单卡无法容纳,必须依赖多机多卡分布式推理。这就要求权重与 KV Cache 不断在各 GPU 及服务器节点间通过高速互连总线通信分发。Runtime 优化的最大核心挑战,在于使互连通信时间与 GPU 计算时间精确重叠重合(Overlap),防止流水线出现空转“饥饿”(Starving)而卡在最慢的木桶短板上。这也正是当前 AI 推理优化赛道各路公司竭力压榨性能的关键所在。

[46:20](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2780s) 软件优化的巨大杠杆:从五倍性能提升到自动化系统

在 AI 模型的推理与部署环节,软件层面的优化空间大得惊人。英伟达曾宣称,在其新一代 B200 硬件架构上运行某个 120B 开源模型时,仅仅通过两个月的纯软件优化,性能就直接翻了整整五倍;而 OpenAI 也对外提到,通过深度的系统级优化,他们让自身的高阶模型 GPT-4o 取得了大幅度的推理性能跃升。这种优化绝非单点单线的工作,而是涵盖了多个层次的纵深协同:包括底层的算子优化(kernel-level)、运行时的调度优化(runtime scheduling)、编译层面的模型计算图优化(compiler-level),以及最上层的集群算力资源调度。要想把这些优化做好,核心在于构建合理的抽象层(abstraction);一旦抽象层稳固,许多繁复琐碎的调优工作就能逐步交由 AI 接管。

这也引出了优化工程师未来的职业路径变革。肖志斌创立 ZFlow.AI 的初衷,正是希望把整个优化流程全面自动化。目前传统的 AI 系统调优严重依赖真实硬件,但真机资源不仅极其昂贵,而且线上部署环境无法支撑穷举式的“if-else”参数探索。为了打破这一瓶颈,团队打造了一整套工具链: - **全栈系统仿真器**:模拟编译前的静态行为、运行期的动态行为,以及底层 GPU 硬件的物理特性(如 Kernel 执行效率和启动开销 Kernel launch overhead)。 - **自动化 Profiling 工具**:在真实执行中采集细粒度硬件与运行时数据。 - **仿真模型校准**:将 Profile 数据反哺给仿真模型,持续校正虚拟环境的精度。 - **AI-Native 闭环**:借助 AI Agent 将仿真、编译优化、动态调度与性能剖析串联起来,使系统能够脱离实体机集群,在虚拟硬件上实现自动调优迭代。

```mermaid flowchart TD accTitle: Automated AI System Optimization Architecture accDescr: Diagram illustrating ZFlow.AI toolchain connecting profiler, simulator calibration, and AI agents.

subgraph HardwareLayer ["物理硬件与执行环境"] HW["真实 GPU / 集群"] --> Profiler["自动化 Profiling 工具"] end

subgraph SimulationLayer ["虚拟仿真与编译优化"] Profiler -->|"真实开销与耗时数据"| Calibration["校准仿真模型"] Calibration --> Sim["AI 系统仿真器<br/>(静态/动态行为、Kernel 开销)"] Compiler["编译器级别优化"] <--> Sim Runtime["运行时调度优化"] <--> Sim end

subgraph OrchestrationLayer ["智能协同闭环"] Agent["AI Agents (全自动编排)"] --> Compiler Agent --> Runtime Agent --> Sim end ```

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[49:15](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=2955s) “内存墙”的本质:大模型底座与海量上下文的双重重压

在大规模计算的讨论中,SRAM、DRAM 与 HBM 构成的“内存墙”(Memory Wall)始终是绕不开的核心痛点。存储介质在物理形态上主要分为两大体系:一是作为运行内存的 DRAM(高速堆叠的 HBM 本质上同样是 DRAM 的一种高阶形态),二是主要作为持久化存储的 NAND 闪存(如闪迪 SanDisk 生产的 SSD 固态硬盘)。当下之所以被“内存墙”死死卡住,背后有几个关键因素: 1. **模型权重的膨胀**:随着参数规模从百亿级跃迁至千亿甚至万亿级,仅为了把模型权重视为静态常驻加载到 DRAM/HBM 中,就需要吞噬海量显存。 2. **KV Cache 的线性甚至超线性暴涨**:解码生成过程中产生的中间键值缓存(KV Cache),与输入的上下文长度(Context Length)以及并发请求数(Concurrency)成正比例攀升,长文本与高并发会让显存瞬间见底。 3. **海量数据的搬运与持久化**:人类生产的数据与大模型输出的海量生成内容需要落盘,模型训练过程中频繁保存的 Checkpoint 权重,以及推理过程中为了腾挪显存必须换出(Offload)的中间 KV Cache,都让存储系统承受着前所未有的吞吐压力。

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[51:06](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3066s) 芯片流派之争:GPU 并不适合解码,Groq 与数据流架构的异军突起

针对数据在算力核心与显存之间的来回搬运痛点,业内涌现了诸如 Groq 推出的 LPU(Language Processing Unit)这类非传统架构。GPU 在本质上是一台吞吐量极大的流式处理机器(Streaming Machine),高度擅长大规模并行矩阵乘法,因而天生完美适配训练(Training)与推理中的 Prefill(预填充)阶段。然而在逐字生成的 Decoding(解码)阶段,GPU 的计算单元大部分时间处于空闲等待状态,算力利用率严重失衡,并且每一轮自回归计算都必须通过 HBM 大量搬移数据,这让高昂的算力被内存带宽瓶颈死死勒住。

Groq 的逻辑与肖志斌在读博期间研究的 Manycore DSP 处理器非常相似,本质上属于**数据流架构(Dataflow Architecture)**: - **数据常驻片上**:Groq 几乎放弃了板载外置 DRAM/HBM,将模型与任务数据全部置于片内超大容量 SRAM 中。 - **流水线数据调度**:任务像水流一样在各个处理核心间按照流水线推进,完全依赖编译器在软件层面进行极致的周期级调度,从根本上消除了片内与片外内存之间频繁搬运数据的物理开销。 - **GPU 的代偿与妥协**:GPU 本身并非数据流机器,业内近年来出现的 FlashAttention 等优化,实际上都是软件工程师绞尽脑汁“在传统 GPU 身上模拟数据流计算模式”,力求让数据在片内驻留更久、尽量减少访存动作。正因架构存在物理代沟,类似 Groq 的架构在低延迟纯推理场景中展现出了惊人的速度优势。

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[53:11](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3191s) 晶圆级巨兽:Cerebras 的 Wafer-Scale 豪赌与工程挑战

在与 Groq 同样聚焦片上超大 SRAM 与数据流架构的阵营中,AMD 在 Advanced AI 发布会上展示了与芯片独角兽 Cerebras 的推理集群深度合作。Cerebras 与 Groq 在逻辑思路上大同小异,都致力于让计算完全摆脱外挂 DRAM,但 Cerebras 走向了一条极其激进的物理工程路线——**晶圆级引擎(Wafer-Scale Engine, WSE)**。

常规芯片量产的路径是:将芯片网格印刷到一整块晶圆上,然后切割(Dicing)成一枚枚独立的裸芯片(Die),将合格的裸片挑出来单独封装,最后通过印刷电路板(PCB)的走线完成系统级互联。而 Cerebras 的做法颠覆了这套范式:它不切割晶圆,而是把整张 300 毫米晶圆直接作为一整颗巨型芯片进行封装,晶圆内部各个核心之间通过硅片上预先蚀刻的原生布线直接通信。

这种晶圆级整合避免了繁琐的板级封装互联衰减,换来了惊人的片上通信带宽与超大规模 SRAM 池,但也带来了三重近乎极限的工程难题: - **垂直供电难题(Vertical Power Delivery)**:普通芯片可以从芯片边缘引脚接入电源,但面对一整张晶圆,边缘引脚根本无法将电流送入核心腹地,必须在晶圆垂直方向穿透供电。 - **极致散热管理**:超大面积的完整晶圆在高负荷运算时发热惊人,整片热量极难导出,需要极其特殊的定制化液冷和热膨胀应变控制。 - **晶圆缺陷与容错绕障**:半导体工艺必然存在瑕疵(Defect rate)。传统工艺只需将坏点所在的 Die 废弃,而 Cerebras 整张晶圆必然包含坏块,必须在硅片网络层设计极其冗余的硬件旁路互联机制,动态绕过故障核心。

尽管 Cerebras 是一项让人赞叹的硬核黑科技,甚至成功说服了台积电(TSMC)配合其定制工艺,早期还获得了包括 Sam Altman 在内的硅谷顶尖投资人重注,但行业内对于晶圆级单点突破是否是唯一解仍有探讨。许多架构师认为,通过 3D 堆叠(3D Stacking)以及成熟的高速封装互联技术,同样可以在相对受控的良率和成本下解决芯片扩展难题。然而,Cerebras 走在行业前列所探索的垂直供电等技术经验,如今也正迅速成为数据中心下一代算力芯片的标准演进方向。

[57:39](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3459s) SambaNova and the Dataflow Alternative to Groq and Cerebras

Examining the recent explosion of ultra-fast inference demos, the conversation turns to the specialized silicon startups making waves in Silicon Valley. Beyond the familiar headlines around Groq and Cerebras, SambaNova represents a distinct, pragmatic branch of architecture. Founded largely by Xiao Zhibin’s former colleagues from Oracle—including the CEO, who is a close personal friend—SambaNova was established to commercialize a reconfigurable dataflow architecture tailored for AI workloads. Interestingly, their initial vision paired AI dataflow processing with hardware acceleration for enterprise databases, though the database functionality saw limited adoption over time and faded from public focus.

Where Cerebras commits to radical wafer-scale integration and Groq leans into deterministic pure SRAM, SambaNova opts for a deliberate compromise. Pure on-chip SRAM architectures hit an unforgiving wall when models outgrow the physical silicon, forcing clusters to scale across ever more chips simply to hold model weights. SambaNova mitigates this limitation by pairing an extensive SRAM footprint with off-chip DRAM and, in later generations, High Bandwidth Memory (HBM). This hybrid dataflow topology allows the chip to retain dataflow execution efficiency while accommodating expansive model weights without demanding exponential silicon acreage.

- **SambaNova's Origins**: Spun out by veteran computer architects from Oracle, with an early hybrid mission of accelerating both AI dataflow and relational database workloads. - **Architectural Philosophy**: A pragmatic middle ground that avoids pure-SRAM scaling bottlenecks by combining generous on-chip SRAM with high-capacity external memory (DDR and HBM). - **The Capacity Trade-Off**: Avoids the Cerebras dilemma, where models exceeding on-chip memory require chaining together massive, costly chips simply to provide sufficient aggregate SRAM.

```mermaid flowchart TD accTitle: Architectural Approaches to Large Model Inference accDescr: Comparison of memory and execution paradigms across Groq, Cerebras, SambaNova, and traditional GPUs. subgraph PureSRAM["Pure On-Chip SRAM (Extreme Bandwidth, Finite Capacity)"] Groq["Groq: Deterministic TSP & Pure SRAM"] Cerebras["Cerebras: Wafer-Scale Engine Pure SRAM"] end

subgraph HybridDataflow["Balanced Hybrid Architecture"] SambaNova["SambaNova: Reconfigurable Dataflow + SRAM + HBM/DDR"] end

subgraph CommodityGPU["Traditional General Purpose"] NvidiaGPU["NVIDIA GPU: SIMT Tensor Cores + HBM Stack"] end

PureSRAM -->|"Fast decode, high chip-count for large weights"| Tradeoff["Inference System Trade-offs"] HybridDataflow -->|"Flexible dataflow with deep memory buffers"| Tradeoff CommodityGPU -->|"Massive ecosystem, bounded by memory bandwidth"| Tradeoff ```

[59:13](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3553s) Bridging the Process Gap: How Much Silicon Deficit Can Software Erase?

When geopolitical barriers or supply shortages restrict access to bleeding-edge fabrication nodes—capping hardware at 7nm or 12nm while competitors deploy 5nm, 3nm, or 2nm—the core question is how much of that physical deficit can be reclaimed across software, algorithmic tuning, and system infrastructure. Xiao Zhibin breaks the performance chasm down to first principles. The pure physical hardware advantage of 2nm over 7nm sits at roughly 2x to 3x, dictated by logic transistor switching power at equivalent clock frequencies, raw compute density, and high-speed SerDes interconnect throughput. However, because SRAM bit-cell scaling has largely stalled from 5nm down to 3nm and 2nm, the actual real-world hardware delta is narrower than raw node numbers imply.

On the software and algorithmic front, Xiao Zhibin asserts that disciplined co-design can readily claw back a 2x to 3x performance multiplier. Techniques like compute-memory disaggregation, aggressive low-precision quantization, speculative decoding, multi-token prediction, and runtime dynamic scheduling dramatically compress latency and arithmetic overhead. On top of that, standard industry hardware utilization hovers around a meager 30% to 50%; tightening orchestration can elevate real-world utilization to 80% or 90%, effectively doubling effective compute without touching the silicon.

There is an unavoidable paradox: the party wielding 2nm chips can theoretically implement the exact same software optimizations. Yet in practice, well-capitalized teams iterating on top-tier nodes often treat software casually, as rapid silicon replacement cycles make hyper-specialized system optimization economically inefficient. Conversely, teams constrained by process limitations are compelled to push system-level co-design to its absolute limits, driving breakthroughs out of pure necessity despite steep engineering and human resource costs.

- **The Hardware Gap**: 2nm delivers approximately a 2x to 3x performance ceiling over 7nm, driven by logic density, power efficiency, and SerDes interconnect speeds, though diminished SRAM scaling softens the blow. - **The Algorithmic Cushion**: Quantization, speculative decoding, multi-token prediction, and compute-memory separation collectively recover a 2x to 3x efficiency gain. - **Utilization Recovery**: Elevating production cluster utilization from the typical 30%–50% baseline up to 80%–90% closes an additional major tranche of the hardware deficit. - **The Innovation Squeeze**: Process-constrained environments pay a high engineering cost in human capital, but constraints force system innovations that well-funded hardware leaders rarely bother to explore.

[01:02:35](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3755s) The Myth of the Sluggish Giant: NVIDIA’s Startup Execution and Supply Chain Moat

While the software and application ecosystem often views NVIDIA as an entrenched monopoly moving at a measured, methodical pace, insiders within the semiconductor and computer architecture space see the exact opposite. Xiao Zhibin highlights that within the chip industry, "NVIDIA is the company with the strongest execution," operating with the aggressive speed and architectural bravery of an early-stage startup. Where rival semiconductor teams spend years publishing academic papers and debating theoretical trade-offs, NVIDIA makes swift, uncompromising architectural bets. When they decided to integrate 2:4 structured sparsity into their Tensor Cores, they hardened it straight into mass-market silicon while competitors remained stuck in research phases. Their tight feedback loop with frontier model developers enables architectural refinements to appear in silicon faster than anyone else in the industry.

This relentless pace extends to audacious strategic M&A. NVIDIA's acquisition of Mellanox was executed with decisive speed, immediately absorbing a high-speed networking architecture whose software stack was initially foreign to CUDA, neutralizing a potential platform threat and anchoring NVLink/InfiniBand at the heart of AI clusters. As Xiao Zhibin points out, this agility stems directly from being a founder-led company under Jensen Huang, unencumbered by the bureaucratic inertia typical of corporate tech giants.

Beyond pure architecture and execution speed lies an equally unassailable barrier: supply chain hegemony. Even if an agile challenger designs an inference ASIC theoretically superior for a specific workload, designing on paper is trivial compared to securing volume allocations of TSMC's advanced CoWoS packaging and bidding against NVIDIA for scarce HBM wafer capacity. As long as Jensen Huang remains at the helm, NVIDIA's moat combines cutthroat silicon agility with ironclad supply chain control, making their market position look virtually bottomless.

- **Startup Speed at Enterprise Scale**: Rapidly bakes radical concepts into production silicon (e.g., hardware-level 2:4 sparsity) while competitors linger in academic research. - **Founder-Led Agility**: Jensen Huang's decisive leadership enables high-stakes, rapid-fire structural moves like the multi-billion-dollar Mellanox acquisition. - **Supply Chain Chokepoint**: Paper architecture advantages evaporate without secured access to TSMC advanced packaging capacity and global HBM production quotas.

[01:05:43](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3943s) The Quest for Cheap Tokens: System Co-Design and AI as a Public Utility

Reflecting on chronic outages across frontier AI platforms—such as Claude's API repeatedly collapsing under overwhelming user traffic—the discussion turns to identifying the ultimate bottleneck throttling inference. While raw compute chips, HBM shortages, networking fabrics, and electrical power grid constraints all create friction, Xiao Zhibin identifies the foundational bottleneck as the absence of continuous, agile system-level co-design. Workloads are rapidly shifting toward complex agentic workflows, long-context reasoning, and multimodal inputs, each exposing massive, unharvested optimization margins in memory access and scheduling.

Solving the inference crisis requires an obsessive pursuit of lowering the marginal cost per token until large models become "as cheap as tap water," transforming intelligence into an abundant public utility alongside water and electricity. Xiao Zhibin remains deeply optimistic that this transition is inevitable rather than merely aspirational. Engineers across the semiconductor stack are attacking memory walls through distributed inference schemes, advanced KV cache compression, novel interconnect fabrics, and next-generation memory form factors—with the entire R&D pipeline increasingly accelerated by AI itself. While macro constraints like physical power grids and foundry wafer capacity will dictate the deployment timeline, the architectural path to radically cheaper inference is already well underway.

- **The Primary Inference Bottleneck**: A persistent deficiency in continuous, rapid system-level co-design capable of adapting to shifting multimodal and agent workloads. - **The Utility Horizon**: The ultimate benchmark for the AI infrastructure transition is reducing inference expenses until tokens are "as cheap as tap water." - **Engineering Trajectory**: Aggressive software optimizations (KV cache management, distributed inference) paired with hardware innovations (advanced interconnects and memory devices) are steadily breaking through memory bandwidth and latency limits.

[01:07:55](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4075s) 物理世界的枷锁与软件端算力浪费:自动化系统优化的契机

芯片与算力基础设施的降本提速,终究逃不开物理世界的硬性法则。肖志斌指出,以美国为例,眼下面临着严峻的电力短缺,而无论是修建一座发电厂还是铺设高压电网,建设周期往往都在五年以上;晶圆制造也是同理,从产能扩充到先进制程的推进,再到阿斯麦(ASML)光刻机每年的实际交付配额,无一不是受制于物理世界的执行节拍。尽管顶尖的工程师们正在竭尽所能一步步拆解并解决这些难题,但在客观的产能与制造速度制约下,单靠硬件制造把 AI 成本打下来的时间周期必然十分漫长。

物理世界的扩张受限,反衬出软件层面上巨大的效率黑洞。在肖志斌看来,当前软件对计算资源的浪费堪称惊人,大量数据中心内 GPU 的真实利用率极低。由于当下大模型结构变化太快、硬件迭代日新月异,整个行业一直疲于奔命,几乎没有人能够腾出手来针对具体模型与硬件进行极致、精准的系统级调优。只有当高昂的成本或物理极限真正形成倒逼时,这种精细化优化才会被视为刚需。而面对庞大的参数空间与架构组合,传统的人工调优已难以为继,必须走向自动化——这正是肖志斌创办 ZFlow.AI 的初衷:将团队多年来深谙的 AI 芯片系统与软硬件协同架构知识沉淀下来,赋予 AI Agent 调用能力,实现软硬件全链路的持续自动化优化。

- **电网与基建周期**:新建电厂或电网扩建的落地周期通常超过 5 年,AI 算力爆发迅速撞上物理能源与基础设施墙。 - **软件端显卡空转**:现存算力集群中 GPU 整体利用率普遍处于较低水平,算力浪费现象严重。 - **系统优化自动化**:通过 AI Agent 将复杂的体系结构优化工程自动化,克服人工无法跟上模型与硬件快速迭代的困境。

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[01:09:55](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4195s) 走出象牙塔加盟甲骨文:为什么年轻人要选择“全貌型”创新项目

访谈在持续硬核探讨了一个多小时后,视角转回到肖志斌个人的职业轨迹。2012 年,肖志斌从加州大学戴维斯分校(UC Davis)博士毕业,在学术界、各大芯片巨头与知名软件企业之间,他最终出人意料地选择了甲骨文(Oracle)。吸引他的关键,在于甲骨文当时刚刚成立了一个做“软硬件协同设计(Hardware-Software Co-Design)”的全新团队,旨在从芯片微架构底层直接加速数据库的核心运算。在 AI 浪潮爆发之前,传统半导体行业分工极其固化,初出茅庐的年轻工程师进入大厂,往往只能如同打怪升级一般,常年困在某个具体模块、单一功能块(Block)或者验证(Verification)流程中,极难获得从头到尾亲历完整芯片架构周期的机会。而甲骨文在收购 Sun Microsystems 后,希望立足自身的核心商业数据库业务打造全新架构,由此催生了著名的“硅上软件(Software in Silicon)”团队,为新人提供了一个极为难得的全貌视角平台。

月球大叔对这种职业路径选择深表赞同,并结合读者的求职困惑给出了建议:年轻人在刚走出校门时,应当优先去往能够看清整个产业链工作流的地方,哪怕是一家充满未知的新兴 AI Infra 公司,其成长收益也远高于回到传统大厂去维护祖传的老旧代码。当然,肖志斌也十分通透地体谅到每个人的现实抉择,坦言如果有工作签证、身份状态或养家糊口的刚性压力,选择稳定悠闲的大厂无可厚非;但若无后顾之忧,年轻人就应尽可能投身于能开拓全局视野的前沿创新项目。

```mermaid flowchart TD accTitle: Career Path Tradeoff accDescr: Comparison between choosing an innovative cross-stack project versus a conventional rigid big tech role. subgraph Innovative["创新协同路径(如 Software in Silicon / AI Infra)"] A["纵览全局工作流"] --> B["软硬件协同跨层设计"] B --> C["高强度挑战与快速认知迭代"] end subgraph Traditional["传统成熟大厂流水线"] D["局限于细分模块 / 验证环节"] --> E["祖传系统打补丁"] E --> F["流程固化但工作节奏稳定 / 签证友好"] end ```

---

[01:14:02](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4442s) 软硬件协同设计的权衡:DAX 加速器与 OZIP 实时解压缩架构

任何系统的微架构设计本质上都是一门权衡(Trade-off)的艺术,“天下没有免费的午餐,你必须决定舍弃什么”。肖志斌详细复盘了当年在甲骨文“Software in Silicon”项目中,其核心加速引擎 DAX(Data Analytics Accelerator)所面临的最关键抉择。该加速器主要由两部分构成:一部分是从内存中高速搬运数据的内存处理单元,另一部分则是专门处理查询的查询处理器(Query Processor,即数据库加速计算单元)。由于数据库分析瓶颈往往卡在内存带宽与数据吞吐上,团队做出的最核心决定是:在内存中全面采用压缩格式存储数据,当数据流被读入加速器时,以硬件流水线的方式进行“边解压、边计算(on-the-fly decompression and query processing)”,实时筛选提取有效数据并将结果写回。

这一方案的核心挑战在于专用压缩算法与硬件架构的绑定。一旦硬件写死了某种压缩算法,未来如果客户的数据类型发生变化导致压缩率暴跌,芯片设计就将面临巨大风险。肖志斌主导了其中压缩算法架构与微架构的设计实现,他们研发并落地了一套名为 OZIP 的压缩体系。为了兼顾灵活性与硬件吞吐,架构采用了基于码字表(Codeword Table)的查找表方案: 1. **预扫描与建表**:针对在线分析查询(OLAP)场景下数据变动并不频繁的特性,系统预先扫描数据库并生成对应的压缩码字表; 2. **硬件预加载**:在加速芯片执行查询任务前,将该 Codeword Table 提前预载入芯片内部的高速缓冲; 3. **流式硬件解压与过滤**:查询请求进入加速器后,硬件通过码字查表快速将压缩流解开并立即送入算子执行,避免了无效数据在总线上的搬运; 4. **动态容错与重构**:若数据库后续发生大批量数据更新导致模式漂移,系统允许重新扫描数据库生成新的码字表,重新加载使用,从而在硬件固化与业务演进之间找到了最佳平衡点。

---

[01:17:10](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4630s) 巨头的底蕴:白菜价收购 Sun Microsystems 带来的技术红利

回顾甲骨文当年在硬件架构创新上的底气,很大程度上源于其在 2009 至 2010 年间对科技巨头昇阳电脑(Sun Microsystems)的世纪大收购。月球大叔向观众科普了 Sun 当年的神级地位:作为上世纪 90 年代硅谷最炙手可热的标杆公司,Sun 之于那个时代恰如今天的英伟达或谷歌,孕育了无数划时代的技术资产与开源生态。

然而在经历了互联网泡沫破裂后的沉沦,甲骨文最终仅以约 74 亿美元的代价就将整个 Sun 收归囊中。肖志斌表示,这笔收购让甲骨文直接吸纳了 Sun 麾下海量极其顶尖的底层硬件架构师与系统工程师团队;而从技术资产来看,这笔交易可谓“便宜到了极点”,打包收编了包括 SPARC 系列精简指令集 CPU 芯片部门、著名的 Solaris Unix 操作系统、企业级存储系统,以及软件史上最核心的两大支柱——Java 编程语言生态与开源关系型数据库 MySQL。正是这些深厚的软硬件跨界资产与顶级人才储备,才为后来甲骨文在 SPARC 处理器上推进软硬件协同设计的“Software in Silicon”构想奠定了工程基石。

[01:18:19](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4699s) Oracle收购Sun与SPARC架构的衰落

肖志斌回顾了Oracle当年以70亿美元收购Sun Microsystems的往事。他直言这笔交易在当时看来极其便宜,因为Sun拥有极其深厚的垂直整合能力:不仅具备自主CPU设计能力,还坐拥数据库、Solaris操作系统以及强大的运行时调度系统。在当时的组织里,任何技术环节遇到疑难杂症,都能直接找到负责该领域的顶尖专家。然而,这种高度垂直整合既成就了当时的Oracle,也埋下了最终失败的隐患。

这个软硬一体的项目最终未能取得长远成功,核心症结出在SPARC处理器上。SPARC拥有自己独立的指令集,与市场上日渐普及的x86架构完全不兼容。随后,x86搭配开源Linux系统组建的小型服务器逐渐崛起,彻底统治了数据中心服务器的主流市场。原本SPARC配合Solaris的组合在商用领域处于统治地位,但由于Solaris没有选择开源,未能建立起繁荣的外部生态,导致在SPARC平台上开发软件的开发者越来越少。整个生态系统日渐萎缩,陷入恶性循环,最终Oracle直接裁撤了整个SPARC部门,肖志斌所在的团队也因此整体受到波及。

```mermaid flowchart TD accTitle: SPARC生态衰落与x86 Linux崛起机制对比 accDescr: 展示封闭的SPARC加Solaris由于缺乏开源生态逐渐萎缩,而x86结合Linux凭借开源生态成为数据中心主流的演进路径。

subgraph Sun_Oracle["Oracle / Sun 封闭垂直整合"] A["SPARC 自研指令集 CPU"] --> B["Solaris 闭源操作系统"] B --> C["缺乏外部开发者 & 生态收窄"] C --> D["整个部门解散 / 项目停滞"] end

subgraph Open_Ecosystem["x86 开源开放生态"] E["x86 标准化服务器芯片"] --> F["开源 Linux 系统"] F --> G["互联网大厂采用 & 开发者繁荣"] G --> H["成为现代数据中心绝对主流"] end ```

[01:19:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4784s) 开源的多维博弈:国家、企业与工程师个人的价值取向

主持人借由当时的行业动态——黄仁勋带头倡导拥抱开源大模型生态——将话题引向深层探讨:开源对于一个国家、一家企业以及工程师个人,究竟意味着什么?

肖志斌指出,硬件层面的开源其实极其罕见。除RISC-V等少数开源指令集或开源IP外,绝大多数底层硬件IP(例如SerDes高速接口等)都属于闭源专利,必须花大价钱购买商业授权。真正驱动互联网繁荣的是软件开源。过去Google发表的多篇底层分布式系统与数据库论文,结合通用x86服务器与开源Linux系统,以及随后发展起来的大数据开源生态,奠定了上一代互联网爆发的技术底座。

从不同维度的利益视角来看,开源的意义和策略各不相同:

- **对企业而言**:大模型开源是一笔复杂的经济账。头部的先行者投入了极其高昂的算力和资金来训练前沿模型,一旦完全开源,很难回收巨额研发成本(ROI),本质上变成了“为所有人做嫁衣”。但对于行业后发者(跟随者)而言,开源则是扩大自身生态阵地、在竞争格局中反超的常规战术。同时,对于下游使用模型的企业,开源模型意味着更低的使用成本、更高的合规与安全性,还能作为与商业大模型巨头谈判的制衡筹码。 - **对国家层面而言**:开源同样受制于先发与后发的博弈。如果中国在大模型领域处在绝对领先位置,策略也未必会全面开源;利用开源去加速追赶行业领跑者,是科技史上后发追赶者屡试不爽的战略选择。 - **对工程师个人而言**:开源毫无疑问是绝对有益的。工程师通过参与复杂的开源项目不仅能磨砺技术,更重要的是技术栈具备了高度的可迁移性(Transferable Skills),换公司时个人能力可以直接复用。此外,开源模型让开发者能够独立部署专属的私有Agent,实现对私有数据的完全掌控。

[01:24:09](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5049s) 职场成长路径:从Oracle架构师到国内互联网自研芯片团队

谈到自己在Oracle仅用五年时间(2012至2017年)便晋升为Principal的经历,肖志斌谦虚地解释,当时Oracle内部存在一定程度的职级通胀,其Principal与NVIDIA等公司的同名头衔在含金量上略有差异,但确实是一次快速的阶跃。他认为自己脱颖而出的核心在于跳出了传统芯片工程师的框框——普通工程师往往是拿着现成Spec(设计规范)去写代码实现,而他做的是软硬件协同设计(例如针对数据库数据压缩的软硬件架构协同设计),更倾向于架构师(Architect)层面的全盘统筹与资源协调,凭借对项目的实际影响力(Impact)赢得了认可。

2017年左右,肖志斌选择回国加入国内头部互联网大厂的芯片自研团队。当时全球大型云计算厂商(Hyperscalers)纷纷启动造芯计划,但团队入局之初,甚至连“到底该造一颗什么芯片”都没有明确定义。

正是这种高度模糊的状态吸引了他: - **从架构师跨界为产品经理**:不再仅仅关注芯片微架构设计,而是站在业务真实需求与商业ROI的角度去评估,调研不同业务场景是否值得固化为专用芯片(ASIC/专用加速器),寻找投入产出的确定性。 - **经历从0到1的完整闭环**:以大厂内部创业(Internal Startup)的模式,全面经手芯片前期的方案定义、外部IP选型采购,甚至亲自参与和晶圆代工厂(Foundry)的首份商业合作协议签署与评估。 - **在不确定性中建立秩序**:“架构师的本质,就是从最初的任务定义出发,在不确定性中去寻找确定性,然后一步步把问题彻底解掉。”通过把模糊、开放式的大问题逐步拆解为清晰的工程落地路径,肖志斌为日后彻底走向独立创业打下了全栈式的认知基础。

[01:28:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5324s) The "Zero-to-One" Mindset and the Shift from Architect to CEO

The conversation opens with reflections on career choices and personality traits. The host notes an alignment with Xiao Zhibin’s preference for tackling open-ended problems and building solutions "from zero to one" rather than optimizing existing systems "from one to 100." Xiao agrees that such opportunities are rare, explaining that building AI chips from a blank slate inside an internet giant like Alibaba provided an environment fundamentally distinct from traditional chip firms. That blank-canvas experience laid the groundwork for his entrepreneurial path.

After serving as Chief Architect at a previous startup, Xiao decided to step up as CEO at ZFlow.AI. He contrasts the two roles and industries: in a pure chip company, the business model is predictable—a team spends two years designing a chip, and if it is competitive, follows an established playbook to sell silicon, reference boards, and software stacks with high go-to-market certainty. In AI infrastructure, however, the industry evolves at breakneck speed. Xiao realized that identifying the right product form—deciding whether to sell software subscriptions, provide engineering services, or offer consulting, and figuring out how to price them—presents an entirely new challenge. Because few leaders can bridge deep technical innovation with business model discovery, he felt compelled to take the CEO role himself to drive both sides forward.

- **Career philosophy**: Xiao thrives on defining problems from scratch ("zero to one") rather than scaling mature products ("one to 100"). - **Silicon vs. AI infrastructure models**: Traditional chip go-to-market follows a rigid multi-year hardware lifecycle, whereas AI infrastructure demands continuous experimentation with pricing, packaging, and commercial delivery.

---

[01:31:39](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5499s) Balancing BD, Technical Direction, and Fundraising Strategy

When asked how he divides his time across product, sales, marketing, technology, and fundraising, Xiao explains that business development (BD) absorbs the largest share of his energy. He spends the bulk of his days engaging prospective customers, negotiating MOUs, and co-defining product-market fit and commercial packaging. While he maintains a comprehensive grasp over technical architecture and product definitions, he intentionally limits fundraising to condensed, focused windows rather than letting it become a perpetual drain.

```mermaid flowchart TD accTitle: Startup CEO Focus and Capital Strategy accDescr: Diagram illustrating Xiao Zhibin's balanced allocation of time and focus between business development, product architecture, and fundraising.

subgraph CoreFocus["Day-to-Day Leadership"] BD["Business Development & Customer MOUs"] Tech["Product Architecture & Technical Nuance"] BD --- Tech end

subgraph Milestones["Milestone-Driven Flywheel"] Model["Validated Business Model & Low Burn Rate"] PayingUsers["Paying Commercial Customers"] NaturalFunding["Natural Investor Demand & Fast Fundraising"] Model --> PayingUsers PayingUsers --> NaturalFunding end

CoreFocus --> Milestones ```

The discussion touches on contrasting philosophies of startup finance. While some Silicon Valley founders leverage relentless, aggressive fundraising as their core competitive engine, Xiao’s hardware background leads him to prioritize capital efficiency and business viability first: - **Low burn rate**: Maintaining lean operations prevents urgency from forcing compromises in strategy. - **Fundraising as a byproduct**: Xiao emphasizes proving value and securing paying enterprise users first, noting that "fundraising is just a natural byproduct" once real commercial demand is demonstrated. - **Role execution**: Acknowledging that CEO capital-raising prowess is a legitimate superpower for some competitors, he prefers to focus on business mechanics so subsequent financing rounds can close swiftly.

---

[01:34:13](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5653s) Optimizing DeepSeek-V3 on B200: Simulation-Driven vLLM Tuning

The host brings up ZFlow.AI's recent benchmark announcement optimizing DeepSeek-V3 inference on NVIDIA B200 clusters, which demonstrated a 1.5x improvement in peak throughput alongside a 2x to 3x reduction in P99 tail latency. Xiao explains the technical roadmap behind these results. Supporting DeepSeek-V3 on an 8x B200 system from "Day Zero," ZFlow utilized its proprietary simulation framework to systematically explore deployment topologies and identify optimal runtime parameters.

```mermaid flowchart LR accTitle: ZFlow Simulation-to-Deployment Pipeline accDescr: Pipeline showing how architectural simulation models DeepSeek-V3 on 8x B200 systems to output optimal configurations for real-world vLLM deployment.

subgraph SimPhase["Virtual Simulation Environment"] ModelSpec["DeepSeek-V3 Architecture"] SimEngine["ZFlow Simulation Engine"] ConfigOpt["Optimal Configurations<br/>(P-D Split, GPU Ratios)"] ModelSpec --> SimEngine SimEngine --> ConfigOpt end

subgraph RealWorld["Production Deployment & Validation"] VLLM["vLLM Runtime Framework"] Hardware["8x NVIDIA B200 (Neocloud)"] Results["1.5x Peak Throughput<br/>2x-3x P99 Tail Latency Reduction"] ConfigOpt --> VLLM VLLM --> Hardware Hardware --> Results end ```

Rather than conducting brute-force trial and error on scarce physical hardware, the simulation determined critical architectural settings—such as whether to implement Prefill-Decode (P-D) disaggregation and how to divide GPUs between prefill and decode stages. Once calculated, these parameters were configured directly into the vLLM engine. Xiao notes that translating simulation insights into real clusters required intense engineering, because early open-source releases of DeepSeek-V3 and vLLM suffered from numerous concurrency and throughput bugs that had to be stabilized manually.

- **Hardware and model**: DeepSeek-V3 deployed across an 8x NVIDIA B200 GPU node. - **Performance gains**: 1.5x higher peak inference throughput and a 2x to 3x drop in P99 tail latency. - **Simulation-guided tuning**: Discovered the optimal split between prefill and decode workers without needing weeks of physical cluster trial and error.

---

[01:36:23](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5783s) A Neutral Architectural EDA Platform for Heterogeneous AI Infrastructure

Addressing community frustrations with the operational complexity of open-source runtimes, the host asks what distinct advantage ZFlow.AI offers compared to internal optimization efforts from chip manufacturers or open-source contributors. Xiao explains that ZFlow provides a virtual simulation backend that integrates directly with runtime ecosystems. By operating as an "architectural EDA tool," it enables teams to simulate, evaluate, and optimize runtime configurations long before deploying workloads onto physical GPUs, dramatically lowering experimental costs.

Furthermore, Xiao highlights a fundamental strategic distinction: major chip vendors build internal simulators solely to promote their own proprietary silicon, whereas ZFlow.AI is committed to being an open, vendor-neutral platform. The framework models heterogeneous combinations—such as pairing NVIDIA systems with AMD hardware or non-NVIDIA accelerators—allowing operators to search for the most cost-effective training and inference configurations without vendor lock-in.

When the host asks whether the reported 1.5x speedup was merely simulated, Xiao clarifies that the benchmark was fully validated on physical hardware supplied by cloud partner Neocloud. The simulation engine's correlation with physical reality has achieved impressive fidelity: - **Prefill stage prediction accuracy**: Exceeds 90% alignment with actual runtime metrics. - **Decode stage prediction accuracy**: Consistently lands between 80% and 90%. - **Industry positioning**: Serving both as an architectural EDA tool for chip designers during early tapeout planning and as a data center optimization engine for large-scale AI operators.

[01:39:11](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5951s) 动态行为的仿真挑战与“AI Token Factory Simulator”

仿真工具在实际运行中面临的最大难题在于各种动态行为(Dynamic Behaviors)。由于实际运行时环境变化多端,纯仿真很难直接根据特定的数据分布做到绝对精准,只能提供各类场景模拟。肖志斌透露,ZFlow.AI 目前能够将仿真精度做到接近 90%。主持人追问这种动态是否是指用户请求到达的时间间隔、系统负载乃至运行温度等因素。肖志斌证实了这一点,并进一步补充,动态行为还包括批处理大小(Batching)、并发动态(Concurrency Dynamics)以及 MoE(混合专家模型)中的专家调度策略(Expert Routing)。当数据分布发生变化时,专家路由路径也会随之改变。要捕捉这些极为复杂的动态行为,通常需要借助 Profiling(性能分析数据)对仿真模型进行校准(Calibration)。

肖志斌指出,团队作为拥有芯片和计算机体系架构背景的从业者,通过这种方法自底向上驱动优化,在业界是非常独特的。然而其核心难点在于:如何在系统抽象与仿真精度之间求得平衡?在做分布式推理(Distributed Inference)仿真时,网络建模本身就极为庞杂——包括网络拓扑结构(Topology)、交换机(Switch)仿真的精细度、路由算法仿真,以及是否需要仿真拥塞控制算法(Congestion Control)等,团队必须精准判断仿真要做到何种程度才“足够支持优化决策”。如果没有亲手搭建过极其复杂真实的底层系统的经验,根本无法将其抽离出一套可行的抽象框架。

主持人感叹这听起来就像是在构建一个“虚拟数据中心”。肖志斌非常赞同,提到黄仁勋(Jensen Huang)在 GTC 大会上也提出过类似的设想,将其称之为“AI Token Factory Simulator”(AI Token 工厂仿真器)。尽管挑战巨大,但肖志斌坚信这套抽象一定能做出来,因为相比于通用 CPU 上跑的传统算法,AI 工作负载(Workload)的确定性和可预测性依然相对更高。

```mermaid flowchart TD accTitle: AI Simulation and Optimization Calibration Flow accDescr: Diagram showing how AI dynamic behaviors and real-world profiling feed into calibrated simulation models to drive system optimization.

subgraph DYN["动态行为挑战"] D1["请求到达与并发负载"] D2["Batching 动态机制"] D3["MoE 专家调度与路由"] end

subgraph ABS["体系架构与网络仿真"] A1["系统拓扑抽象"] A2["交换机与路由精度"] A3["网络拥塞控制算法"] end

subgraph CAL["校准与落地输出"] C1["Profiling 性能实测数据"] C2["仿真模型校准 (~90% 精度)"] C3["AI Token Factory 级系统调优"] end

DYN --> ABS ABS --> C2 C1 --> C2 C2 --> C3 ```

---

[01:42:25](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6145s) 全栈自动化调优:从模型 Serving 到 Agent 级优化

主持人结合肖志斌公司的技术架构指出,除了底层 AI 基础设施仿真外,他们还做了两层关键优化工具:一方面是面向模型推理 Serving 的自动化调优(AutoTuner)以及显存与内存(RAM)管理;另一方面则是面向 Agent 层的开放调优(AutoTuner)。主持人推测,上层负责处理用户请求交互与模型调用,下层负责显存分配与计算拓扑。肖志斌确认了这种理解,并解释这构成了两级优化体系: - **Serving 级优化**:聚焦于底层的显存分配、算子执行与模型单体推理性能。 - **Agent 级优化**:根据用户行为与多 Agent 协作流,智能决策模型选取、内存配置以及端到端的最优部署策略。

肖志斌强调,当前行业虽然拥有众多的 AI 芯片、开源框架和 Agent 推理流,但每一种业务场景的参数配置都千差万别。如果完全依赖庞大的工程师团队纯手工去排查和微调,边际成本极高且极具维护痛点。因此,ZFlow.AI 的核心理念就是用自动化优化(Automated Optimization)的方法,将 Serving AutoTuner 与 Agent Inference AutoTuner 结合起来解决该问题。

---

[01:43:46](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6226s) 商业化困境:借鉴数据库查询优化器与类比 VMware 虚拟化

主持人联想到传统数据库领域的发展历史,指出很多做“Auto”自动化优化的数据库公司日子都过得非常艰难。肖志斌深有共鸣,直言数据库中早有类似技术——查询优化器(Query Optimizer)。优化器需要根据数据特征决定计算是走 CPU、任务 Offload 卸载到何处、以及内存如何分配。数据库里的随机、动态和数据依赖行为(Data-dependent Behaviors)甚至比 AI 更加繁杂;AI 虽然有 MoE 和 Batching,但本质上大部分仍是固定的矩阵运算,随着 AI 系统越来越接近复杂数据库,随机行为也会增多,底层优化算法也有共通之处。

然而,做数据库加速与优化器的独立公司极难成功存活。肖志斌剖析了背后的核心商业困境: - **技术栈过深且迭代极快**:软硬件更迭频繁,专门做优化器的纯软件团队往往跟不上底层硬件演进的节奏。 - **自研挤压生存空间**:头部数据库厂商自己也会内置优化器,第三方难以找到立足点。 - **AI Infra 的资源绑定属性**:AI 基础设施领域的公司必须走向两极之一——要么自身能带来深度信任且强绑定的超级大客户,要么手握庞大的 GPU 物理算力资源。纯做推理或算法优化的独立团队很难仅凭软件壁垒在生态中站稳脚跟。

主持人指出,这种中立仿真底座虽然极具商业化挑战,但一旦做成价值不可估量。它不仅能让开源社区和其他非英伟达芯片厂商免去巨额试错成本,甚至可以直接充当任何 AI 芯片或 Infra 公司的“外包架构团队”,具备极高的并购价值。主持人进一步将该模式类比为当年的 VMware:早期大家也看不清虚拟机抽象层的商业前景,但后来它却成为了所有云厂商不得不部署的基础底座。肖志斌表示赞同,指出黄仁勋全力推 AI Token Factory Simulator 也是因为意识到 AI 软硬件系统已经复杂到了人力极限,不仅昂贵,而且大量 AI 厂商根本没有足够的真实 GPU 资源和能力进行实机调优。

---

[01:48:15](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6495s) 人才断层与全栈实战壁垒

谈及 AI 系统工程的门槛,主持人和肖志斌一致认为,除了硬件资源短缺外,全行业也极度匮乏能够胜任该级别调优的顶尖架构人才: - **门槛远超应届生能力范畴**:现代 AI 软硬件栈的技术深度极其夸张,刚毕业的学生无论学历多高,根本无法直接接手复杂的全栈性能调优。 - **人才来源极为单一**:市面上真正能做底层优化的工程师,要么是在工业界深耕底层 GPU 硬件架构和微体系结构多年的老兵,要么是在 TVM、LLVM 等开源编译和底层系统社区浸润多年、掌握海量实操知识的技术骨干。 - **全栈云落地实战经验不可替代**:肖志斌提到,自己团队最大的壁垒正是全员均为实战派(Practitioners),不仅亲手从零搭建并上线过全栈 GPU 云平台,还在真实的超大规模 GPU 集群中踩平了所有底层的软硬件坑。这种从硬件底层一直通透到上层调度系统、并能将其系统化抽象出仿真器的人才组合,在当前市场上是极度稀缺的。

[01:48:57](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6537s) Building a Veteran Team: Solving Their Own Architectural Problems

Xiao Zhibin sheds light on the founding team behind his venture, ZFlow.AI, describing a small, highly concentrated core of seasoned specialists. Rather than staffing up with generalists, the team was assembled from trusted former colleagues, peers, and students with whom Xiao shares a deep, battle-tested camaraderie. Among them is a graduate school peer who has published research at Hot Chips and spent years designing complex architectural simulators. Xiao’s own background in hardware-software co-design complements this skill set, creating a tight-knit group that intimately understands where hardware and software collide. Because they have spent their careers wrestling with chip simulation and microarchitectural bottlenecks, Xiao explains that they are essentially building a product to "solve our own problem of how to optimize and how to design the architecture."

The host, Uncle Moon, observes that being their own first batch of users gives them an invaluable edge, marveling at the sheer depth of tacit knowledge embedded in their heads. In an era where younger engineers lean heavily on AI agents, Uncle Moon notes that newcomers often do not even know how to begin extracting that caliber of institutional wisdom. Xiao acknowledges that in the semiconductor world, true expertise is earned almost entirely through trial, error, and painful missteps. Because manufacturing and designing chips is so capital-intensive, the experience gained from prior failures is extraordinarily expensive to reproduce and impossible to shortcut.

- **Founding Core:** Composed of a small circle of former academic peers and industry colleagues, including Hot Chips authors and long-time simulator architects. - **Problem-Solution Fit:** The team built the virtual simulation platform to solve the exact architectural profiling and optimization headaches they encountered during decades of chip design. - **The Value of Scarce Experience:** In semiconductor engineering, intuition cannot simply be queried from an AI agent; it is accumulated by surviving costly mistakes on real-world silicon projects.

---

[01:50:20](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6620s) The Silicon Valley Salary Gap: Capital Expenditure vs. Zero Marginal Cost

The discussion turns to a historical paradox in Silicon Valley: despite the extreme technical difficulty of semiconductor engineering, chip designers have historically earned significantly lower salaries than their peers in consumer internet and enterprise software. Xiao recounts how many of his former peers abandoned hardware to become software coders, leaving only a dedicated few to grind away in semiconductors. When Uncle Moon asks why this disparity existed, Xiao explains it through the mechanics of corporate capital allocation.

In a traditional chip company, the bulk of the budget is swallowed by massive fixed capital investments: wafer tape-outs, specialized lab hardware, expensive electronic design automation (EDA) software licenses from vendors like Synopsys and Cadence, and proprietary IP blocks. Because non-human capital expenditure is enormous, human payroll is relegated to a secondary cost tier. Furthermore, outside of a tiny cadre of elite architects, the majority of staff function as operators of complex EDA tools, keeping their market compensation capped. In contrast, prior to the generative AI boom, internet companies directed the vast majority of their capital into human talent. Once software code was written, it could be distributed at near-zero marginal cost, generating astronomical software margins that directly subsidized inflated engineering salaries.

```mermaid flowchart TD accTitle: Shift in Corporate Cost Structures from Software to AI Infrastructure accDescr: Flowchart illustrating how software companies are moving from zero marginal cost human investment to semiconductor-style capital expenditure models.

subgraph TraditionalSoftware["Traditional Internet / Software Model"] direction TB S1["Capital Focus: Human Engineering Talent"] --> S2["Software Development"] S2 --> S3["Zero Marginal Cost Distribution"] S3 --> S4["High Margins & Sky-High Tech Salaries"] end

subgraph AISemiModel["AI Hyperscalers & Semiconductor Model"] direction TB A1["Capital Focus: Fixed CAPEX (GPUs, Fabs, EDA, Power)"] --> A2["Infrastructure & Compute Capacity"] A2 --> A3["Revenue Scaled Proportionally to CAPEX"] A3 --> A4["Engineers Primarily Operate AI / EDA Tools"] end ```

---

[01:51:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6704s) The New Paradigm: Hyperscalers as Chip Companies and Large Models as EDA Tools

Xiao points out that this historical dynamic is undergoing a profound inversion. Cloud hyperscalers and frontier AI labs are beginning to look almost identical to traditional semiconductor companies: their balance sheets are now overwhelmed by gargantuan fixed asset investments in GPU clusters, networking fabrics, and data center real estate. Revenue growth is no longer driven by zero-marginal-cost software replication; it is strictly bounded by capital expenditure (CAPEX) and physical compute capacity.

As compute costs displace payroll as the primary expense, the economic role of the software engineer is shifting. Uncle Moon reflects that across modern model training pipelines—from pre-training to post-training fine-tuning and reinforcement learning (RL)—automated systems and foundation models increasingly orchestrate the workflow, diminishing the leverage of junior human engineers. Xiao draws a striking parallel: large language models are effectively becoming the "EDA tools" of the software industry. Software engineers are transitioning into tool operators, mirroring the status of semiconductor layout and verification engineers. While top-tier systems architects will continue to command premium compensation, the broader engineering workforce must adjust to a reality where baseline coding is augmented or automated, reining in the runaway salaries popularized by tech-boom headlines.

- **Hyperscaler Industrialization:** Cloud giants are shifting from human-capital-heavy balance sheets to CAPEX-dominated infrastructure operations where revenue is strictly tied to physical hardware capacity. - **Large Models as EDA:** Software engineering is entering its "EDA era," where developers primarily prompt and operate AI tooling rather than manually constructing logic from scratch. - **Compensation Realignment:** The ultra-high pay packages highlighted by the media will concentrate exclusively among high-level systems architects and frontier specialists, while the general engineering wage curve normalizes.

---

[01:54:03](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6843s) Career Advice in the AI Era: Cultivating an Architect Mindset and Societal Shifts

When Uncle Moon asks whether high school and university students should still consider majoring in computer science or entering chip-related disciplines, Xiao responds with an emphatic yes—provided they aim for the top of the stack. In his view, future professionals cannot afford to be narrow implementers; they must cultivate an "architect mindset." This requires mastering low-level computing fundamentals, understanding end-to-end system interactions, and grasping high-level business models so they can leverage AI tools to synthesize entire products from the ground up: "Everyone needs to become an architect. Put simply, it means you can bridge the gap from top to bottom."

``` ┌────────────────────────────────────────┐ │ High-Level Domain Logic │ │ Business Models & Strategy │ └───────────────────┬────────────────────┘ │ Bridged by "Architect Mindset" & AI-Augmented EDA Tooling │ ┌───────────────────┴────────────────────┐ │ Low-Level Fundamentals │ │ Computer Science & Silicon Physics │ └────────────────────────────────────────┘ ```

At the same time, Xiao offers a pragmatic caveat: if a student lacks genuine passion for the discipline, pursuing the elite architect path will be intensely grueling. For those who do not possess that obsessive drive, the massive productivity gains driven by AI are not necessarily a death sentence. Instead, ordinary developers can live comfortably as skilled AI operators—resembling standard semiconductor engineers who work reasonable hours, avoid toxic "involution" (burnout competition), and enjoy stable, fulfilling lives. On a broader societal scale, Xiao speculates that extreme productivity leaps will eventually ensure universal baseline welfare, though it may ultimately polarize society into a small tier of hyper-productive architects and a vast population that may not need to work in the traditional sense at all.

- **The Architect Mandate:** Tomorrow’s engineers must bridge top-level commercial requirements with foundational hardware-software principles, delegating boilerplate implementation to AI assistants. - **Passion as a Prerequisite:** Reaching the top tier of systems architecture requires enduring rigorous technical discipline; without deep intrinsic interest, the journey is punishing. - **The Balanced Alternative:** AI-assisted development may eliminate the need for hyper-competitive overtime culture, offering standard engineers decent living standards and sustainable work-life balance.

---

[01:55:54](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6954s) Concluding Reflections: Two Decades of Silicon Valley Semiconductor Evolution

Wrapping up the interview, Uncle Moon reflects on the rich, spontaneous nature of the conversation. Because Xiao brought such an overwhelming breadth of historical context and technical depth, the interview naturally evolved into an unscripted, comprehensive retrospective of the past twenty years of Silicon Valley semiconductor evolution. Together, they mapped out the generational technological transitions that shaped today’s AI accelerator landscape, from legacy CPU architectures to modern wafer-scale engines and virtual co-design platforms.

Xiao thanks Uncle Moon for the invitation, acknowledging with a smile that he tended to speak quickly because almost every sub-topic—from architectural simulation to compilation trade-offs—could easily fill a multi-hour technical seminar of its own. Uncle Moon eagerly proposes turning the appearance into an ongoing series, treating this foundational discussion as an overarching prologue before reconvening to break down each technical chapter in granular detail. Both speakers close by thanking the audience for tuning into a marathon exploration of the hardware and software foundations powering the modern AI revolution.

## Notable quotes > [25:50](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1550s) without these three, basically no one could design AI or chips. — 肖志斌

> [23:34](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=1414s) it's hard to disrupt one's own business — 月球大叔

> [01:02:35](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3755s) NVIDIA is the company with the strongest execution — 肖志斌

> [01:05:43](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=3943s) as cheap as tap water — 肖志斌

> [01:14:02](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4442s) 天下没有免费的午餐,你必须决定舍弃什么 — 肖志斌

> [01:19:44](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=4784s) 为所有人做嫁衣 — 肖志斌

> [01:24:09](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5049s) 架构师的本质,就是从最初的任务定义出发,在不确定性中去寻找确定性,然后一步步把问题彻底解掉。 — 肖志斌

> [01:31:39](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5499s) fundraising is just a natural byproduct — 肖志斌

> [01:39:11](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=5951s) AI Token Factory Simulator — 肖志斌

> [01:48:57](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6537s) solve our own problem of how to optimize and how to design the architecture — 肖志斌

> [01:54:03](https://www.youtube.com/watch?v=gxeP0tAm8mc&t=6843s) Everyone needs to become an architect. Put simply, it means you can bridge the gap from top to bottom. — 肖志斌

## Mentioned 肖志斌, 月球大叔, Yale Patt, Jim Keller, 黄仁勋 (Jensen Huang), Sam Altman, 浙江大学 (Zhejiang University), 加州大学戴维斯分校 (UC Davis), 加州大学伯克利分校 (UC Berkeley), 甲骨文 (Oracle), 太阳微系统 (Sun Microsystems), 阿里巴巴 (Alibaba), 含光800 (Hanguang 800), ZFlow.AI, Tenstorrent, 英伟达 (NVIDIA), 台积电 (TSMC), 中芯国际 (SMIC), 三星 (Samsung), 英特尔 (Intel), AMD, Google, 新思科技 (Synopsys), 楷登电子 (Cadence), 明导国际 / 西门子 EDA (Mentor Graphics / Siemens EDA), ASML, 东京电子 (Tokyo Electron), SK海力士 (SK Hynix), 长江存储 (YMTC), SiFive, 晶心科技 (Andes Technology), Groq, Cerebras, SambaNova, OpenAI, VMware, Neocloud, SPARC, Solaris, MIPS, RISC-V, Arm, x86, TPC-H, Palladium, B200, Tensor Cores, NVLink, InfiniBand, Mellanox, CoWoS, HBM, DAX, OZIP, FlashAttention, vLLM, DeepSeek-V3, Qwen-2.5, GPT-4o, TVM, LLVM, Hot Chips

## Video description 英伟达到底强在哪?为什么芯片从 7 纳米做到 2 纳米,重点竟然不是速度?我们天天用的大模型,背后那些芯片到底在忙什么?

这期请到了肖志斌老师,从浙大、UC Davis,到 Oracle、阿里,再到自己创业,过去二十多年,他一直在跟芯片和计算机架构打交道。结果现在,他做起了一家不造芯片、专门帮 AI 系统做优化的公司。

我们从“一颗芯片到底怎么造出来”开始,一路聊到 AI 推理为什么慢、软件能追回多少硬件差距,还有 Groq、Cerebras 这些公司到底在做什么。最让我意外的是:我们做软件的人觉得英伟达日子过得太舒服了,但在他眼里,英伟达竟然是芯片行业执行力最强的公司。

后半段也聊了他的职业选择、创业,以及 AI 时代年轻人还要不要学计算机。

这期信息量真的有点大,我这个做软件的也是一边听一边补课。很多问题都是现场追问出来的,感觉肖老师脑子里装着一整张芯片行业的地图。大家可以慢慢看,一起把这些天天听到、又不太明白的东西捋清楚。

时间轴

0:00:00 精彩预告与嘉宾介绍 0:01:10 二十年芯片从业之路:为什么从造芯片转向系统优化 0:13:10 一颗芯片如何从设计走向量产,AI 又将如何改变这个过程 0:25:50 看懂全球芯片产业链、开源指令集与纳米制程 0:40:55 大模型如何生成回答,AI 推理究竟卡在哪里 0:50:57 GPU 之外的竞争者:Groq、Cerebras 与 SambaNova 0:59:13 软件能弥补多少硬件差距,英伟达的护城河有多深 1:05:43 让 AI 像水电一样便宜,还需要突破哪些瓶颈 1:09:54 从 Oracle 到阿里:职业选择、技术取舍与开源生态 1:29:21 从架构师到 CEO:寻找产品、客户与商业模式 1:34:13 ZFlow.AI 的实践:用虚拟仿真优化真实算力 1:50:46 AI 时代的工程师:薪资变化与年轻人的职业选择

[Source](https://www.youtube.com/watch?v=gxeP0tAm8mc)

中文简报

肖志斌:先进制程提速见顶,软硬件协同可追回三倍算力差距 随着芯片物理缩放与SRAM微缩陷入停滞,AI算力竞争的核心瓶颈已从晶体管制造转向以虚拟仿真和软硬件协同重构系统级能效。 对话全面拆解了从 7nm 到 2nm 制程升级中控功耗重于提速的工程本质,以及芯片从架构定义、EDA 验证到台积电代工的完整产业链壁垒。肖志斌深度剖析了大模型推理在 Prefill 与 Decode 阶段遭遇的内存墙困境,对比了 GPU、Groq、Cerebras 与 SambaNova 等不同硬件架构路线的取舍,并指出纯软件与系统协同调优能追回先进制程 2 到 3 倍的差距。最后,他结合创办 ZFlow.AI 打造架构级仿真平台的实践,分享了从架构师到 CEO 的转变,以及大模型作为软件业“EDA 工具”对未来工程师职业分化的深远影响。 先进制程升级的核心目标已从提升速度转向降低功耗与发热量;从 3nm 到 2nm 单芯片运行速度提升仅约 3%~5%,而 SRAM 存储单元物理缩放停滞正逼迫行业将焦点转移至系统级架构设计。 (34:18) 大模型推理全流程呈现明显计算瓶颈分期:Prefill 阶段为算力密集型,Decode 阶段为极端显存带宽受限型;通过算存分离、动态调度等软硬件协同设计,软件优化可追回 2 到 3 倍的先进制程物理差距。 (40:55) 英伟达的核心护城河不仅是 CUDA 生态,更在于初创企业般的极致工程执行力(如将 2:4 稀疏概念硬化入量产硅片),以及对台积电 CoWoS 先进封装与全球 HBM 产能分配的供应链绝对主导权。 (62:35) ZFlow.AI 基于虚拟仿真在 8x NVIDIA B200 节点部署 DeepSeek-V3,通过仿真确定 Prefill-Decode 分离架构并注入运行时参数,在物理实测中实现峰值吞吐提升 1.5 倍、P99 尾部延迟降低 2 到 3 倍。 (94:13) AI 大模型正演变为软件行业的“EDA 工具”,传统代码编写被自动化接管导致普通开发者薪资曲线面临平准化,行业超额红利将进一步向打通底层物理计算与上层业务落地的系统架构师集中。 (111:44)

Source quotes

[25:50] 肖志斌: without these three, basically no one could design AI or chips. [23:34] 月球大叔: it's hard to disrupt one's own business [62:35] 肖志斌: NVIDIA is the company with the strongest execution [65:43] 肖志斌: as cheap as tap water [74:02] 肖志斌: 天下没有免费的午餐,你必须决定舍弃什么 [79:44] 肖志斌: 为所有人做嫁衣 [84:09] 肖志斌: 架构师的本质,就是从最初的任务定义出发,在不确定性中去寻找确定性,然后一步步把问题彻底解掉。 [91:39] 肖志斌: fundraising is just a natural byproduct [99:11] 肖志斌: AI Token Factory Simulator [108:57] 肖志斌: solve our own problem of how to optimize and how to design the architecture [114:03] 肖志斌: Everyone needs to become an architect. Put simply, it means you can bridge the gap from top to bottom.

Original transcript

[0:00] NVIDIA is the company with the [0:01] strongest execution in the chip [0:03] industry, and for instance, the annual [0:05] delivery volume of lithography machines [0:07] is also a bottleneck. Yes, people think [0:10] that chips going from 7nm to 5nm or 3nm [0:12] are getting faster, but the real focus [0:15] isn't on speed; it's actually on power [0:18] consumption. [0:19] I seem to recall hearing about a [0:20] company in Silicon Valley that even [0:21] wants to solder base models directly [0:23] onto the chip. [0:24] So I believe the next generation of [0:26] great chip companies will actually be [0:28] AI-native chip design firms. You really [0:31] know your stuff; it feels like your [0:33] brain contains the entire history of [0:35] chip development and a map of every [0:37] manufacturer—it's incredible. Because [0:40] once a chip tape-out fails, you might [0:42] lose hundreds of millions of dollars [0:44] and one or two years of...Present. [0:47] Interviewing 100 interesting people in [0:49] Silicon Valley, this is Uncle Yueqiu. [0:51] Today we have invited Mr. Xiao Zhibing, [0:53] a top-tier chip architect with over 20 [0:55] years of experience. He entered [0:57] Zhejiang University in 1999, later [0:59] pursued his PhD at UCD in the US, and [1:01] has been working in the chip industry [1:03] ever since. Let's welcome Mr. Xiao [1:05] Zhibing. [1:05] Thank you, Uncle Yueqiu, for the [1:07] invitation, and hello to all the [1:09] viewers. Let's dive straight in. Your [1:12] 20-year career path is truly [1:14] fascinating. You started by putting [1:17] accelerators into CPUs, then moved to [1:19] dedicated AI chips, and then to sparse [1:22] chips. Now you've founded a system [1:25] optimization company that doesn't build [1:27] chips. For me, seeing this transition [1:31] makes me wonder if the main battlefield [1:33] for AI performance is shifting from [1:36] transistors and chips to software [1:37] optimization and development. How did [1:41] you make this transition? [1:44] That is a very good question. To answer [1:47] first: yes, the battlefield for AI [1:49] chips has shifted from chip design [1:51] itself to system-level design, [1:53] including the design of software for [1:55] these heterogeneous systems. Actually, [1:59] one fortunate thing over my past 20- [2:01] plus years is that what I've done has [2:03] never strayed from my original field; [2:05] it has always been related to chip [2:07] design. To be more precise, it’s [2:11] hardware-software co-design and [2:13] architectural design. As for why I went [2:16] into architecture and chip design after [2:18] starting as an EE major as an [2:20] undergraduate at Zhejiang University? [2:25] It was because I took courses on [2:27] computer organization and computer [2:29] architecture, and there was a famous [2:31] professor at the time named Patt, who [2:34] invented the branch prediction [2:35] architecture in CPUs, who came to teach [2:38] at Zhejiang University. It just so [2:43] happened that I took his course that [2:45] summer, and from then on, I fell in [2:47] love with computer architecture. [2:51] Looking back at everything I’ve done [2:53] over the past 20 years—from my [2:55] undergraduate, master's, and doctoral [2:57] studies to joining Oracle for CPU [3:00] design, working on database [3:01] acceleration chips, and later at [3:03] Alibaba on the Hanguang 800 and AI chip [3:06] design. After that, I started my own [3:10] company making AI chips, and now I’m [3:12] running an AI infrastructure system [3:14] optimization company. In reality, [3:18] I’ve been doing just one thing all [3:20] along: finding ways to make systems [3:22] more effective and helping them perform [3:24] computations more efficiently. I [3:27] actually started out working on DSP [3:29] processors. Back then, while I was an [3:31] undergraduate and graduate student at [3:33] the university, I focused on [3:35] single-core DSP processors. That was [3:37] around 2002 or 2003, during the time of [3:40] projects similar to the 863 Program, [3:42] where there was a push in China to [3:44] support the independent research and [3:47] development of CPUs and DSP processors. [3:49] I was fortunate to be involved in that [3:51] project since my undergraduate years. [3:54] Then, I continued as a graduate student [3:56] at the same university. Participating [3:58] in the forward-design development of [4:00] such large-scale DSP processors while [4:03] being a graduate student there was [4:04] quite rare. So, at that time, my [4:08] graduate research topic was based on [4:10] MIPS—a traditional processor [4:12] architecture—where I worked on [4:14] extending the multimedia instruction [4:16] set at the MIPS processor instruction [4:19] level. Ultimately, this DSP processor [4:23] was designed for something quite simple [4:25] back then: MPEG encoding for VCDs, [4:28] including both audio and video encoding [4:30] . That was my graduate project. As for [4:33] my doctoral project, I pursued it at UC [4:36] Davis. It transitioned from single-core [4:40] DSPs to multi-core DSPs. The problem we [4:47] were trying to solve back then was [4:49] using a multi-core approach for stream [4:51] computing, known as data computing, to [4:54] handle communication problems, video [4:56] encoding tasks, and some big data query [4:58] and sorting issues. This stream-based [5:06] structure is actually very similar to [5:08] what we now call the dataflow [5:10] architecture used in AI processors. [5:14] It’s about letting the data flow [5:16] on-chip, instead of moving the data [5:18] outside of the chip. The data actually [5:24] flows between many multi-core DSP [5:26] processors, and each DSP processor has [5:29] very, very small instruction and data [5:31] memory, and they are connected together [5:33] through some form of interconnection. [5:39] That architecture was actually very [5:41] advanced at the time; each DSP [5:43] processor could adjust its own [5:45] frequency and voltage. This was my [5:47] doctoral research topic. Well, [5:49] Later at Oracle, we advanced to [5:51] supporting database acceleration [5:54] directly within the CPU. Oracle had [5:58] acquired Sun Microsystems around 2015, [6:00] and I joined Oracle in 2017 when we [6:03] were still developing SPARC processors. [6:08] Perhaps many of our listeners are not [6:10] familiar with SPARC processors. At that [6:13] time, SPARC, along with IBM’s POWER [6:16] and x86, were the primary instruction [6:18] set architectures for large-scale [6:21] server CPUs. These servers, combined [6:24] with the Solaris operating system, [6:26] could run for years without needing a [6:28] reboot; they were extremely stable. [6:31] After Oracle acquired Sun, we wanted to [6:34] innovate, but how? Since our focus was [6:39] databases, we thought about placing [6:41] database operations into the SPARC [6:43] processor as a coprocessor or an [6:45] acceleration unit. By sharing all [6:51] memory bandwidth with the CPU, we could [6:54] saturate the CPU's memory bandwidth to [6:56] enable in-memory databases. At the time [7:00] , we used TPC-H—those in the database [7:03] field would know it—which is a [7:05] benchmark containing 22 queries. We [7:12] hardened these operators into hardware, [7:15] designed an instruction set and runtime [7:17] , and integrated them with the Oracle [7:19] database, effectively creating an [7:21] accelerator for Oracle’s query [7:23] optimizer to speed up certain [7:24] operations. I spent about five or six [7:31] years doing this at Oracle. After that, [7:35] I went to Alibaba to work on their [7:37] first-generation AI chip, and later, at [7:40] my previous AI chip company, we worked [7:42] on sparse AI chips. Now, we are [7:49] building Flow.AI. Through all these [7:51] experiences, we ultimately saw that as [7:54] Moore’s Law slows down, improvements [7:56] in computational performance or power [7:58] efficiency at the single-chip level are [8:01] becoming a bottleneck. The true [8:10] bottlenecks are actually at the system [8:12] and software levels, so if what I’m [8:14] doing is no longer a bottleneck, or if [8:16] many companies are already solving that [8:18] single-chip problem, I should focus on [8:20] solving new bottleneck issues. That is [8:28] why we founded Flow; we use [8:30] architectural approaches and [8:32] simulations to guide AI chip design and [8:34] optimize AI systems. We integrated [8:41] model compilation, runtime scheduling, [8:44] and AI system simulation into a unified [8:46] platform, allowing our clients to [8:48] simulate various hardware optimization [8:50] methods even without the actual [8:52] hardware. Especially with AI clusters [8:59] growing larger, many systems engineers [9:02] often lack the necessary hardware [9:04] support. Therefore, our system [9:11] simulation provides them with an [9:13] excellent tool for system optimization, [9:15] which directly improves the efficiency [9:17] of AI models on hardware. We also [9:24] answered a crucial question: which [9:26] model runs most economically on which [9:28] hardware—hardware that might already [9:31] exist or might not even exist yet. By [9:35] combining simulation with automated [9:38] profiling, we address both sides. To [9:41] answer your question, the bottleneck of [9:44] AI systems today isn't really the AI [9:46] chip, but rather the system and [9:48] software. Oh, thank you, Teacher Xiao! [9:52] Listening to you for so long, it feels [9:54] like you've personally experienced it [9:57] all—from VCDs, multimedia, and big [9:59] data to databases, and now AI. Since I [10:02] studied multimedia, I really resonate [10:04] with that. I used VCDs when I was a kid [10:07] , too. Over the past 20 years, it feels [10:10] like you've been personally involved in [10:12] every major technology-related field [10:14] from the perspective of computer [10:16] architecture and chips. Yes, exactly. [10:19] It’s truly an epic history. Listening [10:22] to you, I get the sense of you working [10:24] from within this grand era. I’m a [10:28] software person, not hardware, but I [10:30] can certainly feel that. [10:32] Over the past 20 years, you’ve put so [10:34] much effort into all these different [10:36] areas of architecture and chips. Right, [10:38] especially what you mentioned about [10:40] transitioning now because Moore's Law [10:42] is nearing its end. With Moore's Law [10:44] failing, you focus more on software. We [10:47] can definitely dive deeper into the [10:49] stories of each stage later. [10:51] My company is actually a system [10:52] optimization firm. In reality, all AI [10:56] chip companies, or those planning to [10:58] make chips, need to do what I am doing [11:00] first. So, I wouldn't rule out jumping [11:03] into chip design if we see the [11:05] opportunity; perhaps we might even [11:07] incubate a chip company. Yes. I [11:09] understand what you just said, which is [11:11] if you run simulations and find that [11:13] certain models run better on a specific [11:15] architecture, you might just go and [11:16] build that architecture yourself, right [11:18] ? Exactly, and models have reached a [11:21] point of convergence. For instance, if [11:25] a model can satisfy our needs for a [11:27] specific task, right? Our needs, like [11:31] for a robot vacuum, or monitoring [11:33] vehicles in a parking lot—if these [11:36] specific tasks don't really change [11:38] anymore, then we can absolutely build a [11:40] chip, a dedicated chip, to accelerate [11:42] that process. Yes. I think I heard [11:46] about a company in Silicon Valley that [11:47] actually wants to hard-wire the model [11:49] directly into the chip. Is that what [11:50] they're aiming for? [11:52] That’s a Canadian company called [11:53] Tenstorrent, and Tenstorrent's founder [11:56] is also their founder. Tenstorrent is [11:59] another AI inference chip company, and [12:01] their current CEO is Jim Keller, the [12:03] legendary Silicon Valley architect. [12:07] Their approach is very radical, but I [12:09] think the reason investors still back [12:11] them is that it represents a trend. [12:17] It's possible that for specific tasks, [12:19] models are becoming more solidified, [12:21] and from an economic standpoint, it [12:23] makes sense to hard-wire them into the [12:25] chip. Of course, their architecture [12:31] actually has some flexibility; it's not [12:33] completely hard-wired. They have [12:37] different metal layers on the chip that [12:39] can be re-fabricated. So it's cheaper [12:43] than doing a full re-spin of the chip. [12:47] It's programmable, but the [12:49] programmability requires sending your [12:51] wafers back to the foundry to redo the [12:53] metal layers. Yes. Wow, the layperson [12:57] sees the excitement, but the expert [12:59] sees the real game. Your ability to [13:01] tell the stories of these chip [13:03] companies is incredible. I have a [13:04] feeling this interview is going to be [13:06] very, very fascinating. Since you [13:10] mentioned you might build chips again [13:12] in the future, as someone who really [13:14] has no idea how chips are made, I’d [13:16] love to understand how a chip is [13:18] actually designed and brought to mass [13:20] production. I see. Actually, chip [13:24] design has a very, very long [13:26] development cycle. When we used to make [13:30] CPU chips, it was basically a [13:32] two-to-three-year design cycle, plus [13:34] fabrication, and finally the system and [13:36] software; it could take three to five [13:38] years to reach the market. Recently, [13:43] Nvidia has really set the pace for [13:45] chips, releasing several new ones every [13:48] single year. Starting to build a chip [13:52] is like building a house; we must [13:54] decide what kind of chip to make. Will [13:57] it be an encoding/decoding chip, a [13:59] communications chip like a specific [14:02] Wi-Fi standard, or something more [14:04] general like a CPU or GPU? So, deciding [14:08] what to build is actually market-driven [14:10] . For instance, you might work with a [14:14] hyperscaler or cloud service provider [14:16] that identifies a specific use case, [14:19] such as requiring custom encoding/ [14:21] decoding chips. Take video streaming [14:26] companies, for example—it's quite [14:28] interesting. Since everyone’s phone [14:33] uses different encoding, incoming video [14:35] comes in all sorts of formats. They [14:42] need transcoding to convert these into [14:44] a unified format for server storage, [14:46] and then convert them again for [14:48] distribution based on individual device [14:50] performance and resolution. That [14:55] requires a specialized chip. This all [14:58] starts with identifying the need. If [15:00] you try to handle this with CPUs, [15:02] it’s extremely expensive. In fact, [15:04] many CPUs don't even have that native [15:07] encoding capability, so you’d need to [15:09] add a massive number of CPU servers [15:11] just for this task. So, it starts with [15:15] requirements development, and once [15:17] those are set, the architects step in. [15:20] Architects must balance the PPA—Power [15:23] , Performance, Area, and Cost. They [15:27] decide how large the chip should be, [15:29] what features to include, and how those [15:31] features compare to the competition. [15:35] Because chip competition is cutthroat, [15:37] the top player basically grabs the [15:39] majority of the market, the second gets [15:41] a small slice, and the third or fourth [15:43] might just get the scraps—or nothing [15:46] at all. That’s why you also need to [15:49] conduct market research on competitors [15:51] to ensure your chip won't be obsolete [15:53] in a year or two. This is the [15:56] architect’s job, and they eventually [15:58] produce the final chip spec. Next, we [16:02] have the micro-architect, who takes [16:04] that chip spec—whether it’s at the [16:06] instruction level or the high-level [16:08] block level—and defines the [16:09] structural implementation. Once these [16:13] structures and functions are clearly [16:15] defined, then the micro-architects take [16:17] the stage. How do you turn it into [16:19] realizable hardware? For the same [16:22] function, say an FFT encoder, there are [16:25] countless ways to implement it, and [16:27] each method has different trade-offs. [16:30] This is where microarchitecture comes [16:32] in; the architecture provides the [16:34] constraints, and the microarchitect [16:36] turns it into a microarchitecture. Many [16:40] microarchitects also write RTL, which [16:42] is the hardware description language, [16:45] translating it into hardware [16:46] programming. After that stage, it's [16:49] time for the verification engineers to [16:51] step in. Actually, before the AI era, a [16:57] chip design company typically had a [16:59] ratio of one design engineer to two or [17:02] three verification engineers, so a lot [17:04] of verification engineers were needed. [17:11] This involves functional verification, [17:14] formal verification, timing [17:15] verification, physical verification, [17:18] and simulation before the chip is [17:20] produced; you have to use FPGA-based [17:22] verification or buy large emulators [17:25] from Cadence, like the Palladium, for [17:27] validation. Verification is therefore [17:31] crucial, because if a chip tape-out [17:33] fails, it could mean hundreds of [17:34] millions of dollars are lost. Not to [17:37] mention one or two years of time wasted [17:39] , so verification is extremely [17:41] important. Moving on, after the RTL is [17:45] implemented, it undergoes synthesis, [17:47] then physical implementation, followed [17:50] by place and route, clocking, power, [17:52] and co-design with system vendors [17:54] regarding power delivery and packaging. [17:59] Once the packaging design is done, you [18:02] send it to the fab—like TSMC or SMIC [18:04] —which takes about three to four [18:07] months. What happens during those three [18:10] to four months? After you send them the [18:14] layout, they create masks, building it [18:16] up layer by layer. You can think of it [18:19] as drawing patterns or printing on [18:21] silicon. The complexity of a chip is [18:25] determined by the number of these [18:27] printed layers. Nowadays, it usually [18:31] requires dozens, or even nearly a [18:33] hundred, of these mask sets. Then, [18:36] after three or four months, your wafers [18:38] return, and you have to find a wafer [18:40] testing facility to check if there are [18:43] any defects, which is different from [18:45] functional verification. Finally, once [18:48] the wafer comes back, you have to dice [18:50] it into individual dies. This is to [18:53] ensure yield, meaning there are no [18:55] defects. The foundry guarantees the [18:58] yield of these dies, and then you send [19:00] them to the packaging house to be put [19:02] into a packaged format. Finally, the [19:05] packaged chip needs to be placed on a [19:07] system board by the system manufacturer [19:10] for testing. Then you conduct [19:12] functional verification and various [19:14] laboratory condition tests, and finally [19:16] , you send samples to the customer. [19:18] After sending the samples, the next [19:20] step is mass production. So, the entire [19:23] process is very long, and the entire [19:25] design cycle is also very long. [19:27] Wow, that sounds so long and so [19:29] complicated, oh my god. [19:30] Yes. [19:31] How long is this cycle, eventually [19:33] reaching mass production? Generally [19:35] speaking, we used to say three to five [19:37] years, but for Nvidia's chips, from [19:39] design to development, it takes about [19:42] two years or so. But some chips now [19:45] iterate every year, though in reality, [19:47] their personnel overlap. It means they [19:50] launch a new generation every year, but [19:52] the R&D process might have actually [19:54] started two to three years ago. Mhm. [19:57] So, what we see now, for example, [20:00] Nvidia's B300 or GB300, might have been [20:03] designed two or three years ago. [20:05] Oh, wow, this is really too long. It [20:08] feels like if there are any slip-ups in [20:10] the middle, it would cause huge delays [20:12] and problems. That's right. From design [20:15] to the entire wafer yield, the supply [20:17] chain, the thermal management of [20:19] packaging and testing, and finally, [20:21] your software having to match [20:23] simultaneously—the probability of [20:25] error is very high. This is why chip [20:29] verification is so important. Speaking [20:32] of verification, let me tell a story. [20:37] Back when Jensen Huang was making chips [20:39] , he had nearly run out of money, but [20:41] he spent the last of it to buy an [20:43] emulator. It was used to verify the [20:47] chip, specifically for verifying that [20:50] GPU at the time. This led to him doing [20:53] this before tape-out, because back in [20:55] the day, when making chips, [20:57] verification tools were still very [20:59] limited. So, chips in the past [21:01] basically had to be taped out several [21:04] times to be successful. But later, [21:06] thanks to these verification methods [21:08] and emulation tools, most chips can [21:10] succeed on the first tape-out, with [21:13] only a small number requiring metal [21:15] fixes. But that is also very normal in [21:18] the chip industry, yes. I’ve noticed [21:21] some companies in Silicon Valley [21:22] starting to use agents to intervene and [21:24] take on roles in design and [21:26] verification. What is your take on [21:28] these companies? [21:29] Oh, I’m very familiar with them, as [21:31] many of them are run by my friends. [21:33] They’re doing a lot, though I won't [21:34] name the companies, right. [21:36] Right, right. I think this is a trend. [21:39] Using AI to design chips is currently [21:41] focused on verification, because [21:43] verification is actually quite similar [21:46] to coding. So it’s a bit like a [21:50] coding agent; it has inputs and outputs [21:52] , and there are verifiable simulated [21:54] environments to check whether you've [21:56] made a mistake. That’s why using AI [21:59] for verification is very common, while [22:01] using AI for forward-looking design is [22:04] still relatively rare. As for using AI [22:07] for physical design—like routing or [22:10] floorplanning—companies like Synopsys [22:12] and Cadence are already using it [22:14] extensively. Yes, so I believe using AI [22:19] to design chips is an inevitable trend, [22:22] but there is still a missing piece: how [22:24] to choose the architecture, what kind [22:26] of chip to make, and how to define the [22:29] chip. Currently, such architectural [22:33] tools are still very scarce, and [22:35] architects still need to play a [22:37] significant role. The second point is [22:40] that chip design companies today face a [22:42] major problem when it comes to adopting [22:45] agents or AI agents. Most have their [22:50] own established workflows, so many [22:52] engineers are reluctant to use AI in [22:54] their current work. If you want to [23:00] replace things, you have to rethink the [23:03] entire process in an AI-native way. So [23:08] I think the next great chip company [23:10] will actually be an AI-native chip [23:11] design company. From architecture and [23:16] design to verification and physical [23:18] design, the entire process must use an [23:20] AI-native approach. Currently, I think [23:27] most chip companies are only adopting [23:29] AI as a tool, but to truly maximize the [23:32] value of AI, it must be a new, [23:34] AI-native chip organization. [23:39] Wow, you are very open-minded. You [23:41] firmly believe that there will be even [23:43] greater chip companies in the future. [23:45] Exactly. [23:46] Having seen the ups and downs of so [23:48] many chip companies and experienced so [23:50] many generations of R&D, you believe [23:52] there will be a huge AI-native company [23:54] later that will produce super, super [23:56] impressive chips. [23:57] Yes, or perhaps only such companies can [24:00] survive in the future. But chip [24:04] companies now have their established [24:06] logic, so it's very hard to do this on [24:08] the existing foundation. [24:09] It's hard to disrupt one's own business [24:11] . [24:11] Oh, right, exactly. Wow, looking at it [24:14] this way, there are so many [24:15] opportunities, right? So, we just [24:16] charge forward, and that's it? [24:17] Exactly, exactly. [24:19] So powerful, so powerful. It’s just [24:21] so inspiring. I don't know how many [24:23] students will go into chips after [24:24] watching this show. Good luck, everyone [24:26] . Right, you mentioned many, many [24:27] points earlier. Since I used to work on [24:29] video network transmission, I generally [24:31] know the process you described, but I [24:33] had never considered it from the [24:34] perspective of chip design. However, I [24:36] have heard from many friends [24:37] at YouTube, they said that in order to [24:39] save on YouTube's massive annual video [24:41] encoding and decoding costs, Right, [24:43] they definitely need to create a lot of [24:45] customized hardware for this, because [24:46] that demand is certainly there. [24:48] Demand, yes, and from a TCO perspective [24:50] , the math actually works out. [24:52] Right, it's too big, it's the world's [24:54] number one video company. And the [24:56] second point is, while I was doing my [24:58] PhD, I often heard the word FPGA. Hmm, [25:01] Right, you mentioned FPGA just now as [25:02] well. Yes, [25:03] but it doesn't seem to be as popular in [25:05] the last two years. [25:06] Oh, right. [25:06] Do you have that feeling? Anyway, I [25:08] feel it’s not that popular. Uh, [25:10] actually, it's not currently used for [25:12] mainstream AI data center inference; [25:14] it's just not as effective. But in [25:17] areas like chip verification and [25:19] emulation, it is still used extensively [25:21] . In some scenarios where there is a [25:25] high demand for programmability, it is [25:27] still widely used, even for [25:29] interconnects, such as chip-to-chip [25:31] connections. If the protocol is [25:35] constantly changing, then it might not [25:37] be...once the workload is fixed, it is [25:39] not the most efficient implementation. [25:44] However, for these highly fragmented [25:46] scenarios, FPGAs are still used in many [25:49] cases, yes. Understood. One more [25:51] question: you talked about many roles [25:53] earlier, like architects, [25:55] micro-architects, and verification [25:57] engineers. [25:57] I've often heard the claim that the US [25:59] possesses the world's most advanced [26:01] chip technology, [26:03] and that companies like NVIDIA and [26:05] Apple are exceptionally good at design [26:07] and architecture, [26:08] and yet, they have offloaded all the [26:10] manufacturing... [26:11] Mm-hmm. [26:12] It's outsourced to TSMC, and everyone [26:14] says the US excels at chip design, [26:16] and TSMC excels at chip manufacturing. [26:18] Is this statement correct? [26:20] I think it is correct. In fact, what [26:24] the US truly possesses is IP and EDA. [26:28] Second is architecture and design, like [26:31] RISC-V, which also started in the US. [26:34] Although ARM's architecture is British, [26:37] there's also the X86 architecture and [26:39] instruction-set IP. Then there are the [26:43] EDA companies like Synopsys, Cadence, [26:45] and Mentor Graphics, the three largest [26:47] EDA firms. Without these three, [26:50] basically no one could design AI or [26:52] chips. [26:53] What does EDA stand for? [26:55] EDA is Electronic Design Automation, [26:57] right. [26:58] Oh, what does it mainly do? [27:01] It helps with every step I mentioned, [27:03] which engineers accomplish by working [27:05] with EDA tools. [27:06] So, it's a specialized tool just like [27:09] MATLAB. Exactly. For example, there's [27:13] less done for architecture design, but [27:15] Synopsys has tools like Platform [27:17] Architect. Then, for converting RTL to [27:22] netlists, there are tools like [27:24] Cadence's Genus. For RTL verification, [27:27] there are simulation tools like VCS. [27:31] For IC design, there's Place&Route, [27:34] plus timing verification tools, formal [27:36] verification tools, and even EDA tools [27:39] for package design. Basically, for [27:42] every job function, there's a [27:44] corresponding tool helping the engineer [27:47] do that work, right. [27:48] Are these tools expensive? [27:50] These tools are sold at a very high [27:52] price, and some things are only [27:54] available from these few companies, yes [27:56] . [27:56] Mm. Is the reason they are the only [27:58] ones who have them because they have [27:59] accumulated a vast amount of knowledge [28:01] and intellectual property in these [28:03] tools? [28:03] Actually yes. The EDA industry has gone [28:06] through years of development with [28:08] large-scale mergers and acquisitions. [28:11] These companies acquired many, many [28:13] small startups, eventually [28:15] consolidating into these few giants. [28:18] That's the first point. The second [28:21] point is that the backend—the [28:22] physical design tools—are actually [28:24] designed in collaboration with the [28:26] foundries. So, your physical design [28:30] tools and the manufacturing nodes we [28:32] mentioned, like nanometers, are [28:34] developed together. It requires [28:37] cooperation from the foundries, with [28:39] everyone working together. So, this [28:45] includes the accumulation of capital [28:47] and industry M&A, as well as the [28:49] experience gained from collaborating [28:51] with these physical design and [28:53] manufacturing partners. Mm. [28:59] Wow, the ins and outs of this are so [29:01] profound. Are other countries, [29:03] including China, working on these [29:05] things as well? [29:07] Uh, yes, because the semiconductor [29:09] supply chain is very long. There's [29:13] foundry, which includes logic [29:14] manufacturing plants and memory [29:16] manufacturing plants. [29:18] What does "foundry" mean? [29:20] Foundry actually refers to chip [29:23] manufacturing plants, like TSMC. Yes, [29:26] they all—and in China, there's SMIC, [29:29] and YMTC which does DRAM, and there are [29:32] those doing NAND. There are many [29:34] companies in China, including some FPGA [29:37] companies. Between China and the US, [29:40] they have the most complete supply [29:42] chains, but other countries play a part [29:45] —like ASML in the Netherlands making [29:47] lithography machines, right? And Japan [29:51] has Tokyo Electron for semiconductor [29:53] equipment, and some companies in Japan [29:55] making materials. These are all [29:58] indispensable links in the [30:00] semiconductor industry. Uh, like the UK [30:03] has Arm, right? Arm provides IP. So, [30:07] the most complete categories are really [30:09] between China and the US, but Japan and [30:12] South Korea have their own specialized [30:14] areas, whether it's foundry, equipment, [30:17] or materials. Yes. [30:19] Wow, you really know this like the back [30:21] of your hand. It feels like your brain [30:23] contains the entire history of chip [30:24] development and a map of all the [30:26] various manufacturers. That’s [30:27] incredible. You also mentioned [30:28] something called RISC-V earlier. [30:30] Since I often look at the work coming [30:32] out of Berkeley, I know they are [30:33] particularly good at open-source, [30:35] open-source software, and various RISC [30:37] architectures. But I also know RISC-V [30:39] is an open-source instruction set [30:41] architecture for chips. Right. [30:42] Why do you think they wanted to create [30:44] an open-source instruction set? [30:47] Uh, I think—I remember having some [30:50] discussions with some of the founders [30:52] of RISC-V. At the time, they wanted to [30:57] do some architectural research or [30:58] development, but they had to use a [31:00] licensed architecture. Moreover, it was [31:06] aimed at mobile applications, and it [31:08] was quite expensive and not open enough [31:11] for academic research, so they decided [31:13] to promote this open-source ecosystem [31:15] and build a new instruction set. And a [31:20] new instruction set has many benefits. [31:24] You can design it from scratch, and [31:26] it's highly scalable, designed very [31:27] well, and doesn't need to be compatible [31:30] with a lot of legacy stuff. It’s [31:34] geared toward new workloads, so as for [31:36] this open-source instruction set, I [31:38] think the industry is already using [31:40] RISC-V processors extensively. Even in [31:43] NVIDIA's own GPU chips, there are [31:46] actually many controllers or processors [31:48] that make extensive use of RISC-V. Wow, [31:51] I really didn't know that. But I do [31:53] know there's a lot, both domestically [31:55] and over here, it feels like there’s [31:57] an industry alliance. Yes, there's [31:59] something called the RISC-V Summit, and [32:02] the RISC-V alliance. Many of the [32:05] founders of RISC-V startups are [32:07] actually our friends—our good friends [32:09] , both domestically and abroad. In the [32:12] US, there's SiFive, and other RISC-V [32:15] companies led by them. Then in Taiwan, [32:18] there's Andes, who also do RISC-V. And [32:20] domestically, there are quite a few [32:22] others; many people from the Alibaba [32:24] ecosystem have come out to make RISC-V [32:26] chips, and they are also our alumni or [32:28] friends. Right, it feels like this [32:30] circle is quite small. It’s like, [32:32] everyone more or less knows each other, [32:34] right? [32:34] Ah, yes. Because the chip industry is [32:37] relatively close-knit due to the [32:39] upstream and downstream relationships. [32:41] Even with the current tight US-China [32:43] geopolitical situation, everyone still, [32:45] well, there’s actually still a lot of [32:48] coordination and cooperation when it [32:50] comes to open source. Yes. [32:52] That’s really great, that feeling. [32:54] And I often see that at chip industry [32:56] conferences or academic conferences. [32:59] Hmm. [32:59] Most of the Chinese faces feel like [33:01] they're all schoolmates or colleagues. [33:02] Yes, yes, that’s right. [33:04] Right, and you just mentioned the [33:05] various nanometer processes. [33:06] Let’s talk about this issue of [33:08] nanometer processes. [33:08] Yes, yes, yes. [33:10] I see it in the news every day, all [33:12] kinds of reports: 2nm, 3nm, 5nm, 7nm. [33:14] What do these nanometers actually mean? [33:18] Uh, actually, in the past, a process [33:20] node—like a certain number of [33:22] nanometers—really corresponded to a [33:24] physical parameter in the manufacturing [33:27] process. That was roughly before the [33:31] 65nm node. We know that all our chips [33:37] are composed of transistors, and most [33:39] transistors now have three terminals. A [33:44] gate, a source, and a drain. The [33:48] nanometer measurement used to refer to [33:50] this gate length. Before 65nm, that was [33:54] the case. But after that, this " [33:56] nanometer" designation has become more [33:58] of a marketing term, meaning it [34:00] represents a generation of technology. [34:03] This is not a single-point technology, [34:05] nor does it represent just one physical [34:07] parameter. It could represent a new [34:13] type of transistor, like a FinFET, and [34:15] then its metal pitch, which is because [34:18] wires are stacked on the silicon— [34:19] that’s the metal, the copper [34:21] interconnects or metal interconnects. [34:27] The width of the metal interconnect at [34:29] the bottom-most layer is what's called [34:31] the metal pitch. This pitch is also a [34:36] technical parameter, as is the cell [34:38] size of standard cell gate-level [34:40] circuits, and the density of SRAM, [34:42] which is a type of on-chip memory. All [34:47] these parameters together define a [34:49] generation of technology. Manufacturers [34:52] label them 7nm, 5nm, or 12nm, but in [34:54] reality, there is no single physical [34:57] parameter corresponding to these. [35:00] Moreover, each manufacturer—like [35:02] Samsung, Intel, or TSMC—has 7nm [35:05] processes that are not truly comparable [35:08] to one another. What’s most important [35:13] to compare is, for instance, your [35:15] standard cell—a standard cell is a [35:17] gate, like an AND or OR gate—the area [35:20] of these basic logic units, or the [35:22] density of your SRAM, or the SRAM size, [35:24] or the PPA under a certain design. This [35:30] is what people compare; it’s hard to [35:32] compare processes directly, even if [35:35] they are both called 7nm. [35:37] For us ordinary people, after hearing [35:39] you list so many technical terms, we [35:41] still don’t really understand them, [35:43] but we know it’s very impressive. So, [35:46] regarding the progress of the process [35:48] node itself, for example, moving from [35:50] 7nm to 5nm, [35:51] or from 5nm to 3nm, [35:53] right. What exactly does it solve, what [35:56] has improved, and what problems remain [35:58] unsolved? [36:00] Right, there is actually a [36:01] counterintuitive issue here. People [36:04] think 7nm to 5nm or 3nm just means the [36:07] chip gets faster, but the real focus [36:10] isn't on speed; the real focus is on [36:13] power consumption. That is to say, at [36:17] the same performance level, power [36:19] consumption can potentially be cut in [36:21] half, or the changes—the benefits— [36:23] in power consumption between [36:25] generations are far greater than the [36:27] changes in speed. For example, for TSMC [36:32] , perhaps from N3 to N 2—the 3nm to [36:36] 2nm node—the power savings might be [36:39] 10%to 15%, while the speed increase [36:42] might only be around 3%to 5%. So, [36:46] between each chip generation, power [36:48] efficiency is actually the most [36:50] important factor; power consumption [36:52] decreases significantly while [36:53] maintaining the same performance. [36:55] This is truly the first time I've heard [36:57] this particular phrasing. [36:58] Right, and once power consumption drops [37:01] , in the same rack, for example, you [37:03] can pack in more compute, so the [37:05] computing density can increase. So [37:07] Because the heat dissipation [37:09] requirements also decrease, right? The [37:10] heat generated decreases. [37:12] Yes, the heat also decreases. [37:16] Previously, before reaching 5nm or 7nm, [37:19] power consumption and area actually [37:21] followed what is called Dennard scaling [37:24] , meaning your supply voltage—the [37:26] chip's voltage—would keep dropping [37:29] along with the area. But now, because [37:35] all gates and all transistors have a [37:37] baseline voltage. It can't go down any [37:40] further. So. As everyone knows, a [37:42] chip's power consumption is divided [37:44] into two. Parts: one is static power [37:46] consumption, and the other is dynamic [37:48] power consumption. Static power [37:50] consumption is, well, you can think of [37:52] all these logic circuits as a gate. [37:56] Static power consumption is what you [37:58] get when it is in a stable state, [37:59] whether it's on or off. The power it [38:01] generates then, and dynamic power [38:03] consumption is the power generated [38:05] during the switching state, which is [38:07] called dynamic power consumption. [38:09] Before, at 12nm or even above 16nm, it [38:11] was mainly dynamic power consumption, [38:13] but later static power consumption [38:16] became larger and larger, meaning [38:18] leakage current effects increased. So, [38:20] static and dynamic power consumption is [38:23] a bit complex. [38:24] Hmm, no worries, please continue. I [38:26] think everyone is trying their best to [38:27] follow your line of thought. It's truly [38:29] great because I feel you've already [38:30] tried your best to use the most [38:31] accessible language to help everyone [38:33] understand; people can just watch it a [38:35] few more times to digest it, right? Yes [38:38] , because the technology stack in this [38:40] chip industry is particularly deep, and [38:42] there are just too many technical terms [38:44] , so I'm explaining as much as I can. [38:48] But what everyone should remember is [38:50] that for the entire chip process, for [38:53] instance between 7nm and 2nm, what [38:55] people are mainly talking about is the [38:57] issue of power; it's really about [38:59] reducing power consumption, hmm. [39:01] Therefore, for a 2nm chip compared to a [39:03] 7nm chip, the 2nm chip's power [39:05] consumption might only be a fraction of [39:07] the other's. And because its power [39:09] consumption and heat are lower, you can [39:11] pack more into a single server rack; [39:12] this single rack can then generate [39:14] greater capability, and there's no need [39:16] to move as much data around since it's [39:18] all together. Exactly, exactly, but if [39:21] we go into detail, we could talk for a [39:23] long time. For example, taking AI chips [39:26] , you know that half of the chip is [39:28] logic and half is SRAM, and SRAM is a [39:31] type of on-chip memory. [39:34] And the scaling of this SRAM stops [39:37] somewhere between 7nm and 3nm. As [39:41] process technology goes further, the [39:43] cell size of SRAM doesn't change, which [39:45] is a point many people might not be [39:47] fully aware of. [39:49] Not aware. [39:50] Yes, and the logic portion can indeed [39:53] continue to scale down. Mm. [39:55] So, here is a question: what does this [39:58] mean? [39:58] What does this mean? [40:00] This is very interesting. It brings us [40:04] back to the perspective of AI models, [40:06] where AI model serving involves prefill [40:08] and decoding. Mm. [40:17] If it's compute-intensive, it's helpful [40:20] ; but if it's a memory-bound problem— [40:22] like for companies such as Groq or [40:24] Cerebras, which rely heavily on on-chip [40:27] SRAM—if SRAM cannot scale, then their [40:29] chip design philosophy must change. [40:39] Right. So they have to do other things. [40:43] Yes, or their architectural ratio will [40:45] be different, or they need to do [40:47] something else, such as 3D stacking or [40:49] other things. [40:51] It’s getting too deep; let’s see if [40:53] we can figure this out together later. [40:55] Yes, mm. [40:55] Before we go deep into the interaction [40:58] between these chips and AI, we can [40:59] first provide a brief overview for [41:01] everyone. [41:02] Mm. [41:02] For example, I host a large model in a [41:05] data center. [41:05] Yes. [41:06] Then a user sends a prompt. Yes, yes. [41:09] To this model. [41:10] Yes. [41:10] So, how do the chips in the entire data [41:13] center interact to finally spit this [41:15] out, and keep spitting it out [41:17] continuously? [41:18] Uh, that's actually a very good [41:20] question. We can walk through it; for [41:23] example, after a user says something, [41:25] you generate a prompt, right? Then this [41:27] prompt must pass through your device, [41:29] be sent over the network, and arrive at [41:31] the other side's gateway via the [41:33] network. Then after the network, the [41:37] first step on the server side is a [41:39] large scheduler, meaning your input or [41:41] your prompt, the question you raised, [41:44] has to go through a queuing process. [41:50] Then the scheduler places you into a [41:52] queue, based on the GPU or computing [41:54] resources available. The scheduler then [41:59] solves the problem of what to do next, [42:02] specifically where to send you—which [42:04] server or which GPU. As for the [42:11] question you asked, if there is context [42:13] , there is also an RAG process, meaning [42:16] the relevant data is retrieved from [42:18] your historical context. This data [42:26] might be in a database, on a disk, or [42:28] if it's an ongoing conversation rather [42:30] than one from days ago, it might be in [42:32] the GPU memory. You then combine that [42:39] part with your new question to organize [42:41] an input prompt. Once organized, this [42:46] context needs to be sent to the large [42:48] model. But where is the large model [42:51] actually located when it receives it? [42:55] There is actually a runtime—a piece [42:57] of software waiting for your input. [43:02] Once it receives your context from the [43:04] scheduler, this runtime begins the next [43:06] set of actions. What does it do? It [43:12] loads the model and performs the [43:14] prefill action, which involves sending [43:16] your entire context to the model. The [43:23] runtime loads your model from memory or [43:25] another location into the GPU, and at [43:27] the same time, it can perform batching [43:29] with your context, processing multiple [43:32] user requests together. This is called [43:36] the prefill stage. This prefill stage [43:39] is compute-intensive and allows for [43:41] batching. [43:43] Since there are no dependencies between [43:46] tokens, it is compute-intensive and [43:48] determined by the GPU's computing power [43:50] . After completing this part, it [43:54] generates a magical thing called KV [43:56] cache. Yes, we can refer to Mr. [43:59] Jincheng's explanation of KV cache in [44:02] the second video. [44:04] Right, and this KV cache will be stored [44:06] somewhere, potentially in the GPU, or [44:09] if it's too large, it might be stored [44:11] in storage like flash or an SSD. Once [44:15] the KV cache is ready, the next part is [44:18] the decode stage, where the large model [44:20] starts outputting answers. The answer [44:25] is generated one token at a time, so [44:27] this is called the decoding phase. This [44:33] decoding phase is actually quite tricky [44:35] ; it is a memory-bound, or [44:37] memory-intensive, task. It has to load [44:42] all these KV caches into the GPU and [44:44] process all the weights of the large [44:46] model, just to generate a single token. [44:52] And between tokens, after generating [44:54] one, it creates a new column in the KV [44:57] cache, which must be stored in the [44:59] original KV cache. Then this new KV [45:05] cache and the model must be re-read and [45:07] sent out again to generate the next [45:09] token. So just imagine the massive [45:14] amount of data movement involved; this [45:17] is why data transfer and memory [45:18] bandwidth are such a bottleneck. And at [45:22] the same time, there is another issue, [45:24] which is the interconnection problem. [45:27] This is because current large models, [45:29] such as open-source ones like DeepSeek [45:32] V3 with 671 billion parameters, or Qwen [45:35] 2.5 with 72 billion parameters, are so [45:38] huge that you basically have to use [45:40] distributed inference. So, these KV [45:44] caches or model weights must be sent to [45:47] different GPUs or servers, which then [45:49] requires interconnection and [45:51] communication. You also have to match [45:57] the interconnect communication time [45:58] with the computation time so that your [46:00] pipeline doesn't suffer from "starving, [46:03] " meaning it doesn't stall due to the [46:05] slowest link. So, there is a vast [46:09] amount of runtime work involved, which [46:11] is exactly what many AI inference [46:13] companies are focusing on now. Every [46:16] bit of such optimization can squeeze [46:18] out a little more performance, [46:20] resulting in faster inference or better [46:22] memory efficiency. [46:25] Exactly, so the scope for optimization [46:27] here is huge. For example, NVIDIA [46:31] claims that for their B200 and certain [46:33] models, like an open-source 120B model [46:36] ......they managed to improve [46:38] performance by five times through [46:40] software optimization after just two [46:42] months. Five times! This is... [46:46] Right, OpenAI also mentioned yesterday [46:48] that they improved the inference [46:50] performance of their own advanced GPT- [46:52] 4o model significantly as well, right? [46:56] Yes, there are actually many layers of [46:58] optimization involved here. There is [47:01] kernel-level optimization, runtime [47:03] scheduling optimization, compiler-level [47:06] model optimization, and also resource [47:08] scheduling optimization. Actually, to [47:11] do optimization well, you really need [47:13] to get the abstractions right. Once the [47:17] abstractions are solid, you can hand [47:19] many things over to AI to handle. [47:21] Exactly. [47:23] Then, what will be the career [47:24] development path for these optimization [47:26] engineers in the future? [47:28] Uh, I definitely think so, and that’s [47:31] exactly why we started the company we [47:33] have now. We really want to automate [47:36] this entire process, but we’re [47:38] actually missing a few pieces. For [47:41] example, we first built an AI system [47:43] simulator, and then integrated [47:45] simulation with optimization. We also [47:49] have an automated profiling tool. [47:53] It’s not just simulation—we [47:55] simulate pre-compile static behaviors, [47:57] dynamic behaviors, and aspects [47:59] involving underlying GPU hardware, like [48:02] kernel performance and kernel launch [48:04] overhead. We need all of this to be [48:08] automated. Then we take that data to [48:13] calibrate our simulation model. So, [48:15] we’ve built this complete suite of [48:17] tools that includes simulation, [48:19] compiler optimization, runtime [48:21] scheduling, and profiling. Our goal is [48:24] essentially to solve this optimization [48:26] problem. Current AI still often cannot [48:30] achieve full automation, or it can't [48:33] perform these tasks on virtual hardware [48:35] ; it requires real hardware for more [48:37] iterations. Mm. [48:40] Real hardware means the cost is too [48:42] high, right? [48:43] Real hardware is just too expensive, [48:45] and you also need a real system [48:47] deployed somewhere. And if you have [48:50] that, you can't really do this kind of [48:52] "if-else" style exploration either, [48:54] right? Yeah. Right, but based on your [48:57] description, it feels like... [48:58] Once AI develops for a few more [49:00] generations and captures these specs [49:02] accurately, it seems like it could [49:03] handle the optimization itself. [49:05] Uh, it could, because our company is [49:07] also using AI agents to chain together [49:09] the tools we've built, and it's [49:11] actually doable. [49:12] AI-native, right? [49:13] Exactly, that's right. [49:15] Right, and there’s another question: [49:17] in your description, you mentioned [49:19] large-scale computing, SRAM, DRAM, HBM, [49:21] and things like that are... [49:23] These are the recent "memory walls," [49:25] right? Right. [49:26] Could you explain to everyone which [49:28] part exactly causes this "memory wall"? [49:31] The memory wall is primarily caused by [49:33] models becoming increasingly larger. [49:35] Storage is divided into memory, such as [49:38] HBM and DRAM, and NAND, like the SSDs [49:41] made by companies like SanDisk. The [49:46] reason for the memory wall is, first, [49:48] the DRAM usage when serving models— [49:50] since models are getting bigger. Second [49:55] , the intermediate KV cache is also [49:58] growing, and the KV cache is positively [50:00] correlated with your context length and [50:02] the number of user concurrent requests. [50:07] This involves DRAM, because HBM is also [50:10] a type of DRAM. Another point is that [50:15] we humans are generating so much data, [50:17] and it has to be stored somewhere; plus [50:19] , we need many checkpoints for model [50:21] training. This data is actually growing [50:27] more and more, and content generated by [50:29] AI—including direct output and [50:31] intermediate KVC—may all need to be [50:33] offloaded and stored somewhere. This is [50:37] why storage is becoming increasingly [50:39] crucial. Right, although it has [50:41] plummeted again these past two days, we [50:43] won't go into those specifics, exactly. [50:45] Investing is actually quite interesting [50:48] ; it’s related to the industry, but [50:50] it has its own set of rules and issues [50:52] regarding capital flow. [50:54] This is not investment advice, so [50:56] everyone should manage their own [50:58] affairs. Also, as you just mentioned, [51:01] there's all this data movement, chips, [51:03] and bandwidth. [51:04] Right. [51:05] And so on, mhm. [51:06] A while back, NV acquired that company [51:09] that made TPUs, which is Groq. [51:12] They make what they call an LPU. [51:13] What do you think is the main problem [51:15] they are trying to solve? [51:18] Uh, it’s really about solving the [51:20] fact that GPUs aren't naturally suited [51:22] for this decoding mode. Right, it's too [51:25] obvious; it was designed for training [51:27] from the start. [51:28] Exactly, so a GPU is basically what you [51:30] could consider a high-throughput [51:32] streaming machine. [51:33] It's great at parallel processing. [51:35] Ah, it’s great at parallel processing [51:37] , so it’s very suitable for [51:38] prefilling. [51:39] Right. [51:39] But it’s not suitable for decoding. [51:42] The ratio of computing resources isn't [51:45] right because the GPU is mostly idle, [51:47] and it's constantly moving massive [51:49] amounts of data back and forth using [51:52] HBM. So why is Groq better at decoding? [51:58] Actually, the architecture of Groq is [52:01] very similar to the Manycore DSP [52:03] processor I worked on during my Ph.D. [52:05] Essentially, all task data resides [52:07] permanently inside the chip, and [52:09] through this dataflow pipeline approach [52:11] , a task passes through different parts [52:14] of the chip—let's call them cores— [52:16] and through continuous pipelining and [52:18] software scheduling, it naturally [52:20] avoids the need to frequently move data [52:23] back and forth between on-chip and [52:25] off-chip memory. When data resides [52:30] permanently inside the chip, it's [52:31] efficient. And while GPUs aren't really [52:37] suitable for this, people are now [52:39] trying to simulate these effects—this [52:42] so-called dataflow computation—so [52:44] they've made many optimizations like [52:46] recent FlashAttention; all of this is [52:48] actually to keep data inside the GPU as [52:50] much as possible and minimize movement. [52:58] But ultimately, the GPU is not a [53:00] dataflow machine, so NVIDIA needs an [53:02] architecture similar to Groq's dataflow [53:04] to assist it. Actually, just two days [53:11] ago, I attended AMD's Advanced AI event [53:14] , where AMD is collaborating with [53:16] another similar company, Cerebras, on [53:18] an inference cluster with a [53:20] pre-configured architecture. Right, so [53:25] what is the difference between Cerebras [53:27] and Groq? Actually, in terms of [53:30] architecture and logical design, they [53:33] are very similar; both use this kind of [53:35] on-chip SRAM dataflow architecture. [53:40] They try to keep data resident within [53:42] the chip as much as possible, allowing [53:44] tasks to be mapped onto a single chip [53:47] without needing to access external HBM [53:49] or other DRAM. Then, Cerebras is [53:52] actually doing this wafer-scale [53:54] integration. They’ve developed many [53:57] innovative technologies. Usually, when [54:01] we talk about producing chips, we map [54:03] them onto a wafer, cut them into [54:05] individual dies, and then package those [54:08] dies. Afterward, we connect them via [54:11] system-level interconnects. But [54:16] Cerebras says they don't need to do [54:18] that; they take the whole wafer for [54:20] packaging directly, and the chips are [54:22] interconnected through pre-designed [54:23] traces on the wafer, so each chip [54:25] doesn't need to be cut or packaged [54:27] individually. This so-called [54:35] wafer-scale approach has many benefits, [54:37] the main one being that chips don't [54:39] need to be re-packaged or connected [54:40] through board-level wiring outside the [54:42] package. Instead, they are directly [54:48] interconnected via the wafer-level die. [54:50] But this also brings many engineering [54:52] problems, such as power delivery. [54:55] Originally, you could power a chip from [54:57] its edges, but if you have a whole [54:59] wafer, you don't have enough edges to [55:01] provide power, so you have to innovate [55:03] in power delivery. Too thin, or what? [55:06] Yes, exactly. [55:07] I mean, it's too thin, just like that. [55:10] No, for a single chip, power is [55:12] supplied through the pins on the sides, [55:15] but for a whole wafer, you can only [55:17] supply power to the chips around the [55:19] periphery. So you are forced to [55:21] implement vertical power delivery. The [55:23] second challenge with vertical power is [55:25] that the wafer is very large, so you [55:27] have to handle heat dissipation— [55:29] specifically, how to manage the cooling [55:31] . And the third issue is that every [55:35] chip has a yield rate; traditionally, [55:37] we cut them into dies and discard the [55:39] defective ones, only packaging the good [55:41] dies or chips. But there are bound to [55:46] be some bad chips within that wafer. So [55:50] they have to design an interconnection [55:52] mechanism to bypass those bad chips. [55:56] There’s a lot of engineering effort [55:57] involved there. From my perspective, I [56:01] think Cerebras 'wafer-scale engine is a [56:04] very cool technology, but you don't [56:06] necessarily have to do wafer-scale, [56:08] right? [56:09] There are actually other ways to solve [56:11] this problem. [56:12] Exactly, exactly. [56:13] Are you interested in starting another [56:15] major company to do this? [56:17] Actually, there are some new [56:19] technologies, like 3D stacking or using [56:21] high-speed interconnects to solve the [56:23] scaling problem. So, you personally [56:25] aren't that optimistic about Cerebras, [56:28] right? [56:29] Uh, I think Cerebras has its advantages [56:31] too. Because many chip companies now [56:34] can find specific application scenarios [56:36] where the volume is large enough. At [56:40] the same time, the technologies they've [56:42] been working on are quite innovative, [56:44] like vertical power delivery; most [56:46] chips in data centers today are [56:47] starting to move toward vertical power [56:49] delivery. So, many of their [56:52] technologies are actually ahead of [56:54] others. Perhaps they might design [56:57] something new; we don't know yet, right [56:59] . [56:59] Right, because a lot of innovation [57:00] comes from these kinds of experimental [57:02] and disruptive approaches. [57:04] Exactly, exactly, exactly. Hmm. [57:06] So I think it’s a very great company, [57:09] or a very, very excellent company. [57:11] Designing like that under those [57:12] circumstances, and having TSMC [57:14] cooperate—meaning the manufacturing [57:17] side had to work with them to pull this [57:19] off—was really not easy. And didn't [57:22] it come out a while ago that Sam Altman [57:24] personally invested in a lot of these [57:26] companies early on? [57:28] Uh, that's right. They also saw the [57:33] situation, which follows a similar [57:35] logic to NVIDIA; the Cerebras [57:36] architecture is very well-suited for [57:39] decoding, specifically for this part of [57:41] large model decoding. Yes, we see these [57:46] new chip companies releasing many demos [57:48] where the decode speed is just [57:50] phenomenal. [57:50] Ah, yes, yes, yes. [57:52] Very. [57:53] Yes. It’s impressive. In Silicon [57:55] Valley, from my layman's perspective, [57:57] I've noticed three such chip companies: [58:00] Groq, Cerebras, and SambaNova. What [58:02] does SambaNova do? SambaNova was [58:05] actually founded by many of my former [58:07] colleagues from Oracle. After we left [58:12] Oracle, many people went to SambaNova, [58:14] including the CEO, who is a good friend [58:17] of mine. They were really looking to [58:21] build a dataflow company. It's about [58:25] using a dataflow architecture for AI. [58:28] The initial intent, besides Dataflow AI [58:30] , also included a database function. Of [58:34] course, that database feature wasn't [58:36] widely used later, so many people don't [58:38] mention it anymore. Secondly, its [58:42] architecture isn't as aggressive; it's [58:44] not pure SRAM. While SRAM takes up a [58:47] large portion, it also includes DDR or, [58:50] later on, HBM. It’s a compromise [58:53] architecture. It's not like Cerebras, [58:56] where when a model gets too big to fit, [58:59] it requires more chips. So, it is a [59:02] compromise—a dataflow architecture [59:04] that still incorporates DRAM and HBM. [59:08] Wow, these three companies really have [59:10] their own strengths. [59:11] Exactly. [59:12] Mm. Anyway, with so many chips [59:14] available, plus various manufacturing [59:17] processes, [59:17] and all kinds of different technologies [59:19] . [59:20] At the software level, the algorithm [59:22] level, the data level, [59:24] and this infrastructure level. [59:27] Right. [59:28] How much of this hardware performance [59:30] gap can actually be recovered? For [59:32] example, [59:32] a 2nm or 5nm process, [59:35] Right. [59:35] chip, [59:36] for a large model, [59:37] Right. [59:37] versus the other side that can only use [59:40] 7nm or 12nm. [59:41] Mm. [59:42] How much can the software level help [59:44] bridge that gap? Right. First, we need [59:47] to look at where 7nm actually differs [59:50] from [2nm/5nm], such as the power [59:52] consumption of logic transistors at the [59:55] same performance level—that is, [59:57] compute density—and second, its [60:00] interconnects, such as the supported [60:02] SerDes speed. So, for the difference [60:07] between 7nm and 2nm, I think the [60:09] performance gap is roughly two to three [60:11] times, around three times; you can [60:14] consider that the absolute physical [60:16] limitation. But there is a catch: as I [60:20] mentioned earlier, SRAM doesn't scale [60:23] well from 5nm to 3nm, so the benefits [60:25] of that part might need to be [60:27] discounted. From a purely software [60:35] perspective, if we look at things like [60:38] compute-memory separation, [60:39] low-precision quantization, speculative [60:42] decoding, multi-token prediction, and [60:44] real-time scheduling optimization, this [60:46] part can actually recover about two to [60:49] three times the performance. There is [60:56] another part, which is utilization. [60:59] Through software optimization, we can [61:02] improve the industry-average [61:04] utilization from, say, 30%to 50%, up to [61:07] 80%to 90%. This accounts for another [61:09] part of the gap. I think from a [61:13] software perspective, you can actually [61:15] catch up, but it's hard to say. For [61:18] instance, with the same AI, if I have a [61:21] 2nm chip and you have a 7nm process [61:24] chip, I can still apply the same [61:26] software optimizations. So, if you [61:31] haven't optimized your software well, [61:33] it’s entirely possible to boost the [61:35] performance of your hardware to match [61:37] the level of a process that hasn't been [61:39] optimized. [61:42] In that sense, from a positive [61:43] perspective, no matter what chip you [61:45] get, there is always plenty of room for [61:47] optimization. That's right. [61:48] But the downside is [61:50] Mm. [61:50] Both have room for optimization; even [61:52] the 2nm one has room to improve. [61:54] You can move forward. Yes. [61:56] Yes, both can move forward. It’s hard [61:58] to say. [61:59] Yes, or perhaps some people don't need [62:01] such refined software because their [62:03] chip iteration is too fast, and [62:05] software actually has a cost. So they [62:09] might not need such detailed [62:11] system-level co-design. But if your [62:15] process is restricted, you actually [62:17] need to do more of this system-level [62:19] co-design, and the finer you go, the [62:21] more benefits you get, though it comes [62:23] with higher human and resource costs. [62:26] Mm. [62:26] Mm, that is also why many [62:28] resource-constrained companies are able [62:30] to come up with some great innovations. [62:32] Uh, exactly, exactly, exactly. [62:35] After hearing your description of how [62:37] much can be caught up, I feel like [62:39] NVIDIA's biggest advantage in training [62:41] and inference is being targeted by more [62:44] and more people wanting a piece of the [62:46] pie. [62:47] That's actually correct. As model [62:51] workloads become more fixed, many [62:53] people feel they can customize their [62:55] own inference chips for their specific [62:57] application scenarios. [62:59] Just like back when video was hot and [63:01] everyone started making video chips. [63:03] Exactly, but if you think about it, [63:05] NVIDIA is the company with the [63:07] strongest execution in the chip [63:09] industry, and because [63:10] This is quite different from how most [63:12] people perceive them. For those of us [63:14] in software and AI, we might think NV [63:16] is the most...capable company, but from [63:18] a chip industry perspective, their [63:20] execution is incredibly strong—their [63:22] chip iteration speed is very fast, and [63:24] their pace of architectural innovation [63:26] is also very rapid. It’s a bit like a [63:29] startup. Take NVIDIA's GPU architecture [63:31] , for instance—things like doubling [63:33] sparsity—once they decide to do it, [63:36] they just implement it. Meanwhile, many [63:39] other companies are still writing [63:40] papers and haven't gotten around to it. [63:43] When they do specific optimizations [63:45] based on certain conditions, their [63:47] iteration speed is incredibly fast. As [63:51] soon as they get feedback from the [63:52] model side, like from someone like you, [63:54] they can evolve their architecture with [63:56] the speed of a startup. [63:59] Wow. [63:59] And NVIDIA’s decision to acquire [64:01] Mellanox was also an incredibly fast [64:04] move. Just think about it: acquiring a [64:06] company with a software stack [64:08] incompatible with your own, which could [64:10] potentially pose a threat—they could [64:12] have done it themselves, but they made [64:14] the decision so quickly. This is [64:16] exactly why founder-led companies move [64:19] so fast. That’s the first point. The [64:21] second point is the supply chain. Even [64:23] Jensen Huang mentioned in recent [64:25] interviews that a major advantage they [64:27] have is their control over the supply [64:29] chain. While everyone can certainly [64:31] design an AI inference chip [64:33] architecture that is well-suited for a [64:35] specific scenario, it's another matter [64:38] if you can't secure HBM capacity or [64:40] TSMC's capacity, and your internal [64:42] engineering iteration speed can't keep [64:44] up with NVIDIA's. There are other [64:46] layers of difficulty involved here. [64:49] Your perspective, coming from chip and [64:51] computer architecture, is completely [64:53] different from ours. Those of us in [64:56] software and modeling always felt that [64:58] NVIDIA was just moving slowly and [65:00] meticulously in terms of software. [65:03] I never imagined they had such [65:05] disruptive R&D capabilities on the chip [65:07] side. Exactly. From a software [65:09] perspective, NVIDIA’s pace seems [65:11] relatively slow. But from our [65:12] perspective in the chip industry, their [65:15] pace—or rather, their execution—is [65:17] second to none, I think. [65:18] If that's the case, NVIDIA’s moat in [65:20] chips seems bottomless. It really seems [65:23] that way now. [65:24] I believe that as long as Jensen is [65:26] still leading the company, this [65:28] advantage will continue, yes. Wow, that [65:31] is terrifying. It really goes to show [65:33] that you have to ask the insiders to [65:35] get the deepest insights into these [65:36] things. Oh my, that's fantastic. My god [65:39] , your ability to tell a story is just [65:41] incredible. I can't wait to see how [65:42] amazing this episode turns out. One [65:44] more question. Nowadays, most AI tasks [65:46] are about AI inference. Today, Claude's [65:49] API went down again; it's clear the [65:51] demand is just too high. [65:52] Exactly, exactly. [65:54] Yeah. In your opinion, what is the [65:56] biggest bottleneck for AI inference? Is [65:58] it compute chips, HBM, network systems [66:01] —those interconnects—or electricity [66:03] , or something else? [66:05] Uh, I think it still comes down to a [66:07] lack of compute power. Yes, a lack of [66:09] power. And if we look at it from a [66:11] bottleneck perspective, it's the lack [66:14] of system optimization, the ability for [66:16] continuous optimization. The ability to [66:20] keep lowering the token cost, because [66:22] there are more and more models, chip [66:24] architectures are evolving rapidly, and [66:26] more will follow. Not to mention the [66:31] multimodal models and agent-based [66:33] inference, which actually have huge [66:35] room for optimization. So, what's [66:38] really missing is the ability to [66:40] co-design from a system-level [66:42] perspective, and to do this co-design [66:44] very quickly, to accelerate the [66:46] iteration speed and bring down that [66:48] token cost. We must always pursue the [66:51] ultimate token cost, so that large [66:53] models become as cheap as tap water, [66:55] making AI more accessible. [66:56] Exactly. I believe AI should become a [67:00] utility-like infrastructure, just like [67:02] water and electricity. [67:06] For practitioners like us, this isn't [67:08] just a possibility; it's something that [67:10] will definitely happen. [67:11] It's hard to imagine that after all [67:13] this, [67:13] Yeah. ... [67:14] it will still be this expensive? It [67:16] will definitely come down. Yes, costs [67:18] will certainly go down. The [67:20] semiconductor industry is constantly [67:22] innovating and working hard, including [67:24] the KV cache I mentioned earlier, and [67:26] distributed inference. Besides the [67:29] software side, many new chip companies [67:31] are in the works. Memory is a [67:35] bottleneck, and many device companies [67:37] are developing new solutions, including [67:39] new interconnect solutions. As long as [67:43] there are bottlenecks, engineers are [67:45] very smart; we will solve the problems, [67:47] especially now with the help of AI. [67:51] However, there are things like [67:53] production capacity or infrastructure [67:55] that follow their own rules; they are [67:57] physical constraints. Take the US, for [67:59] example, there's a power shortage, [68:01] right? To build a power plant or a [68:04] transmission grid, it actually takes a [68:07] cycle of over five years—the timeline [68:09] is very long. Manufacturing has its own [68:13] rhythm too, like wafer production. [68:17] Ultimately, everything is stuck on the [68:19] execution speed of the physical world. [68:22] The execution speed of the physical [68:23] world, and for example, the annual [68:25] delivery volume of lithography machines [68:27] , is actually a bottleneck, yes. Mm. [68:30] Right, in the existing environment, our [68:32] brilliant engineers will definitely do [68:34] everything possible to solve the [68:36] problems one step at a time. [68:39] But limited by various production [68:41] capacities and manufacturing speeds, [68:43] the time it takes for costs to come [68:45] down will still be quite long. [68:47] Exactly, exactly. So that is why, if [68:50] the physical world is limited, what [68:52] about software? Currently, the waste of [68:55] computing resources in software is [68:57] actually massive. From my perspective, [69:00] the utilization rate of many GPUs is [69:03] quite low. [69:05] Secondly, there are many features; [69:07] because models change so quickly and [69:09] hardware evolves so fast, no one has [69:11] actually been doing those optimizations [69:14] more precisely. Only when costs or [69:17] physical limitations force everyone to [69:19] do so will these optimizations be done [69:21] with extreme precision, and these [69:23] optimizations must be automated. This [69:27] is also why our company wants to turn [69:29] our knowledge of AI chip systems and [69:31] architecture into something an AI agent [69:34] can invoke, enabling continuous [69:36] automated optimization. [69:39] I firmly believe that your company, [69:41] which is so AI-native, will definitely [69:43] have a bright future, truly. [69:45] Thank you, thank you. [69:46] Yes. Oh, I don't know, this might be [69:48] our first interview that started out so [69:51] hardcore; we've been talking about [69:52] hardcore stuff for over an hour [69:54] straight. [69:55] Let's switch gears a little bit and [69:56] return to your personal story. [69:58] Mm-hmm. [69:59] So, in 2012, you finished your PhD. [70:01] Yes. You could have chosen academia, [70:04] various chip companies, or software [70:06] companies; why did you end up going to [70:08] Oracle? What attracted you to Oracle? [70:10] What attracted you? [70:13] Uh, a main reason for Oracle was that [70:15] it was a new team doing something new, [70:18] and it was a benchmark project for true [70:20] hardware-software co-design. It [70:28] involved accelerating database [70:30] operations on CPU chips, which required [70:33] chip co-design, how to perform [70:35] hardware-software co-design with [70:37] software, and how to iterate with the [70:39] OLTP database. It was actually a very [70:46] complete and innovative project. You [70:49] know, in our chip industry, if you [70:51] really want to do a chip project like [70:53] that from start to finish, before AI, [70:55] it was actually very rare for anyone to [70:58] have such an opportunity. Usually, [71:02] architects are more senior, so if you [71:04] really join a chip company, you might [71:06] just work on a block. You work on [71:10] modules, or some people start out in [71:13] verification. You have to keep leveling [71:15] up like you're playing a game. Back [71:19] then, after Oracle acquired Sun [71:21] Microsystems, they wanted to build a [71:23] new accelerator based on Oracle's [71:25] business, which gave me an opportunity. [71:30] We called that team "Software in [71:32] Silicon," meaning we were building [71:34] software into silicon using hardware to [71:37] implement it. At the time, that team [71:40] was a very innovative project, which is [71:42] why I felt it was such a great [71:44] opportunity. [71:45] It really was rare. In fact, my [71:49] followers are always asking me how to [71:51] choose a company and how to make those [71:53] career decisions. [71:56] Personally, I feel you should choose [71:58] like you did. [72:00] Go to a place where you can see and [72:02] learn about the entire industry. When [72:04] you've just graduated, you're still [72:06] very young. Right, right. [72:08] If you immediately limit yourself to a [72:09] tiny role that is uninteresting and [72:11] lacks challenge, [72:12] that's not ideal. [72:14] Exactly, while you're young, if you can [72:16] find opportunities that give you a [72:18] global perspective, you should do more [72:20] of that. [72:22] For example, if you look at a famous AI [72:25] infrastructure company versus a big [72:27] tech firm working on legacy databases. [72:30] Right. My constant advice is to go to [72:33] that AI infrastructure company first to [72:35] learn the entire AI workflow, rather [72:37] than returning to a big firm for a [72:39] fancy title, [72:40] Yes. [72:41] where you only end up working on things [72:43] from the ancient past. Exactly, and the [72:46] processes there rarely change; you [72:48] might just be patching things based on [72:50] someone else's foundation. Of course, [72:53] that kind of work can be more relaxing, [72:55] as people have different pursuits. Some [72:57] people value stability, or they need to [73:00] solve visa issues, right? In that case, [73:02] the choice is understandable. But if [73:06] you don't have those worries, I think [73:08] it's best to work on innovative [73:09] projects where you can see the big [73:11] picture. That's why my career path has [73:15] basically been about taking on new, [73:18] challenging, and innovative projects. [73:20] Wow, you've maintained such a great [73:22] state of mind. Look at how you talk to [73:24] everyone; from the moment I met you [73:26] until now, you've always been smiling [73:27] and living every day so happily. It [73:29] looks like the kind of work that gives [73:31] you positive energy and helps you level [73:32] up. I really like your current state, [73:35] and [73:35] you're also very thoughtful. You've [73:37] been working for almost 20 years, right [73:39] ? [73:39] Yet you still think about how everyone, [73:41] while graduating, also needs to deal [73:43] with visa status issues, family matters [73:44] , and all sorts of other problems. [73:46] Yes. Oh, you are just truly happy and [73:49] thoughtful. My goodness, you really [73:50] kept yourself in such great shape. [73:52] Thank you, thank you, um. [73:54] So throughout this whole process, [73:56] you've mentioned many times that this [73:58] Oracle project is an innovative one, a [74:00] project designed to accelerate database [74:02] queries. [74:02] In this, what do you feel was the most [74:04] interesting or critical decision made? [74:06] Because in chip or system design, [74:08] anyone who has studied system PhD knows [74:10] it's always about tradeoffs. [74:12] There is no such thing as perfect, [74:14] there’s no free lunch; you have to [74:16] choose what to give up. What do you [74:18] think was the biggest decision that [74:19] helped you or the company grow the most [74:21] ? [74:23] Uh, actually, it's because the DEX is [74:26] composed of two parts: one is the [74:28] memory processing part, which fetches [74:30] data from memory, and the other is what [74:32] we call the query processor, the [74:34] database acceleration engine unit—you [74:36] can think of it as the compute unit. [74:45] The biggest decision we made at the [74:47] time was, we defined a database [74:49] compression format; that compressed [74:51] format sits in memory, and we read it [74:53] in, decompress it on the fly, compute [74:55] on the fly, extract only the data we [74:57] need for calculation, and then send the [75:00] result back to memory. So a huge [75:07] decision we made back then was [75:09] selecting this compression method for [75:11] computation, and we had to choose a [75:13] specific compression algorithm. And, [75:16] well, you know, there are some [75:17] tradeoffs involved. Once you've [75:21] selected this compression algorithm, if [75:23] the data type changes or something else [75:25] changes, and the compression efficiency [75:27] drops, then the risk is actually quite [75:29] high. So, I think the biggest thing we [75:34] did at the time, including the part I [75:36] was responsible for, was developing [75:38] that compression architecture algorithm [75:40] and the microarchitecture for the [75:41] compression. We had a compression [75:45] algorithm at Oracle called OZIP. We [75:49] compared OZIP with software, we did a [75:51] lot of software-based testing to see [75:54] what the compression efficiency could [75:56] reach, and how OZIP was implemented. [76:01] There are many ways to implement this, [76:03] but we ultimately used a lookup table [76:05] approach. When you have a database, [76:09] since I work with queries, the data [76:11] doesn't change too frequently. So, we [76:16] first scan the database and generate a [76:18] compression table, which we call a [76:20] codeword table. Then, this codeword [76:26] table can be preloaded into our [76:28] accelerator before the chip starts [76:30] running. When a query comes into the [76:38] chip, I use that codeword for lookups [76:40] and then decompress the uncompressed [76:42] data. This is followed by the rest of [76:50] the query processing. The advantage [76:54] here is that even if the data changes, [76:56] I can rescan the database to generate a [76:58] new code table for re-decompression. [77:03] Although there is some risk involved, [77:05] we have mitigated it in a certain way, [77:07] which is actually quite interesting. [77:10] Mm. Anyway, I don't quite understand it [77:13] , but I know you must have accomplished [77:15] a lot of extraordinary things over [77:17] these five years. [77:19] Mm. [77:19] So, do you think this project of yours [77:21] is very innovative? You must have been [77:23] quite happy, looking at how you are now [77:25] . [77:25] What do you think are some of the [77:27] biggest advantages of Oracle, and what [77:29] are its most notable shortcomings? [77:30] Well, the advantage of Oracle is [77:32] actually that they bought Sun [77:34] Microsystems back then, so Sun had many [77:36] incredible engineers and architects, [77:38] and we were... [77:39] Let me clarify this for everyone: Sun [77:41] is the company behind Java. Sun is the [77:44] company that created Java, Sun [77:46] Microsystems. In the 90s, they were the [77:49] hottest company, similar to NVIDIA or [77:51] Google today. They also supported many [77:55] open-source projects, but they were [77:57] sold to Oracle for about seven billion, [77:59] which was extremely cheap. Which parts [78:03] were sold? The SPARC CPU chip division, [78:07] the Solaris operating system, including [78:09] Java, MySQL, the whole system, and many [78:12] other things, as well as the storage [78:15] systems—it was all very cheap. [78:17] Looking at it from today's perspective, [78:19] it was extremely cheap, seven billion. [78:22] Seven billion, indeed. And this company [78:26] has excellent vertical integration [78:28] capabilities; we have CPU design [78:31] capabilities, databases, the Solaris [78:33] operating system, and runtime [78:35] scheduling. Anyway, you, you can always [78:39] find someone to ask about anything, so, [78:42] it is a vertically integrated [78:44] organization, which is why Oracle was [78:46] relatively good at that time, and also [78:48] the reason it wasn't. In the end, this [78:51] project wasn't particularly successful. [78:54] Why? It’s because the CPU was SPARC. [78:56] You know, the SPARC processor has its [78:59] own instruction set, and it is [79:01] incompatible with x86. Later, x86 [79:03] combined with Linux to create these [79:05] types of small servers, which became [79:07] the mainstream for data center servers. [79:12] Before, it was SPARC and Solaris, but [79:14] because Solaris wasn't open-sourced, [79:17] the company failed to make it open at [79:19] the time, which meant the ecosystem [79:21] wasn't prosperous enough, leading to [79:23] fewer and fewer developers building [79:25] applications on SPARC, and thus the [79:27] ecosystem failed to thrive, becoming [79:29] weaker and weaker, so the whole project [79:32] wasn't particularly successful. [79:37] Regarding the SPARC processor, later on [79:39] , Oracle actually laid off the entire [79:41] department, basically our whole team at [79:44] the time. [79:44] Let’s set aside the layoffs for a [79:46] moment, let’s talk about what you [79:47] mentioned earlier regarding open source [79:48] . [79:49] Right. [79:49] The biggest piece of news these past [79:51] two days. [79:51] Mm. [79:52] Jensen Huang is taking the lead, [79:53] Mm. [79:54] calling on everyone to embrace open [79:56] source and support [79:57] this open source initiative, openM, [79:59] right? [79:59] More and more companies are joining [80:01] this. [80:01] Right. [80:02] I am also a firm supporter of open [80:04] source. [80:04] Right. Looking back at your past career [80:08] , [80:10] what do you think open source [80:11] means for a country, for an enterprise, [80:14] and for an individual, respectively? [80:16] Wow, that is a rather big question, yes [80:18] . [80:18] It’s quite big, very big, but since [80:20] it’s so important, I feel I must ask, [80:21] even though we hadn't prepared this [80:23] question beforehand. [80:24] That’s true, that’s true. I think [80:26] from a hardware perspective, open [80:28] source is rare; open-source IPs or [80:31] instruction sets like RISC-V are [80:33] actually quite uncommon. And in [80:37] hardware, many IPs are actually not [80:39] open-source, like SerDes or various [80:41] other IPs, everyone has to license them [80:44] . Then, from a software perspective, [80:46] once a chip is designed, it needs [80:48] software and an ecosystem. So, software [80:51] open source is actually what created [80:53] the prosperity of the internet. In fact [80:56] , those few papers from Google, you [80:58] know, the papers on databases, [81:00] including Google’s use of x86 servers [81:02] plus open-source Linux, combined with [81:05] these open-source big data processing [81:07] systems, actually created the [81:09] prosperity of the previous generation [81:11] of the internet. For the entire [81:13] industry and for enterprises, open [81:15] source is absolutely—I am also a [81:17] supporter of open source. It’s [81:20] actually extremely helpful for [81:21] fostering the industry ecosystem, and [81:23] it’s also quite good for us [81:25] individual engineers. Once things are [81:29] open-sourced, we can contribute to more [81:31] complex projects, and at the same time, [81:33] your skills become transferable, right? [81:38] When you move from one company to [81:40] another, you can actually transfer your [81:42] technical skills or your own knowledge. [81:47] However, when it comes to open-sourcing [81:49] models, there is another issue: why [81:51] don't many companies choose to [81:53] open-source? It’s really because they [81:57] spent a huge amount of money training [81:58] these things. If they do open-source [82:02] them, how does the company itself [82:04] measure the ROI? In effect, you’re [82:06] just making a contribution to everyone [82:08] else, right? So, for many of these [82:14] model companies, if they decide to [82:16] open-source, especially for the early [82:18] movers—the leading companies in large [82:20] language models—the big question is [82:22] how they can recover the significant [82:24] initial investment they’ve made. [82:30] Right. [82:30] But latecomers can open-source. [82:33] Open-sourcing allows them to expand [82:35] their own ecosystem. However, [82:40] open-sourcing might not be a great [82:42] strategy for a specific company, so it [82:44] depends on where you stand—whether [82:46] you are a leading large model company [82:48] or a follower. So for companies, there [82:53] are pros and cons, depending on your [82:56] position. For individuals, open-source [82:58] is definitely a good thing. For us [83:01] personally, open-source means you can, [83:03] for example, deploy your own private [83:06] open-source agents, you can do a lot of [83:08] things with open models, and you can [83:10] keep control of your own data. For [83:16] enterprises, if an open-source solution [83:18] can be made more compliant or secure in [83:20] some way, it can lower costs and also [83:23] serve as leverage against those big [83:25] model companies. When it comes to [83:30] national strategy, the issue becomes [83:32] much bigger, and it’s again a [83:34] question of who moved first. If China [83:38] were in the position the U.S. is in, [83:40] China might not necessarily open-source [83:42] either, right? So, latecomers using [83:46] open-source as a way to catch up is a [83:48] fairly common model in the industry. [83:51] Hmm, I think your analysis is extremely [83:53] comprehensive; the whole open-source [83:55] topic is just incredibly complex. Yes, [83:57] exactly. [83:58] There are considerations from various [84:00] aspects, but in any case, for us as [84:02] individuals, I think it is definitely [84:05] beneficial. [84:05] As an individual, always stay [84:07] open-minded. [84:08] Right. Mm. [84:09] So from 2012 to 2017, you became a [84:12] Principal at Oracle in just five years. [84:16] Mm. Honestly, everyone in Silicon [84:18] Valley knows how difficult that is, [84:20] because when you graduate, you start as [84:23] a junior, then senior, and Principal is [84:25] a very, very high-level position. What [84:27] do you think... [84:29] I have to clarify this; at that time, [84:31] Oracle's titles were inflated. Our " [84:34] Principal" wasn't exactly like the [84:36] Principal role at a company like NVIDIA [84:39] , but it was still a pretty good [84:41] position, yes. Right, what do you think [84:45] helped you get promoted and grow so [84:47] quickly? [84:50] Uh, I think it’s mostly about making [84:52] actual contributions to projects [84:54] because the company can see your output [84:56] and your impact. So it's more about [85:01] taking on harder, more challenging work [85:03] . For example, the software-hardware [85:08] co-design for compression I mentioned [85:11] earlier, and to a greater extent, [85:13] coordinating resources and doing things [85:15] differently than traditional chip [85:17] engineers—who are just assigned a [85:19] spec to implement. I was doing more of [85:24] what you'd call architect-level work, [85:26] yeah. [85:28] Mm, you started doing architect work [85:30] very early on, from a higher [85:31] perspective. [85:32] Which naturally pushed you into a much [85:34] larger... [85:35] Position. Right, it really comes down [85:38] to the problems you tackle and the [85:40] projects you take on, yes. [85:43] After that, you joined a startup chip [85:46] team back in China. [85:47] Mm-hmm. [85:48] What made you make that career choice? [85:52] The situation with that company at the [85:54] time was, the background was that every [85:56] hyperscaler was looking into custom [85:58] chips, and every hyperscaler wanted to [86:01] do custom chips. And this company— [86:04] well, let's call it an internet company [86:06] —when we joined, we weren't even sure [86:09] exactly what kind of chip to make. So [86:13] for me, it was a great opportunity [86:15] because you go in, and you're not just [86:17] an architect; you become a product [86:19] manager, someone who has to figure out [86:21] from a business perspective what kind [86:23] of chip to build. In the past, that was [86:27] usually decided by the CTO or CEO of a [86:29] chip company. Then we had to conduct a [86:33] lot of research to figure out which [86:35] businesses were useful, what scenarios [86:37] existed, what the ROI and cost were, [86:39] and whether these business scenarios [86:41] could be distilled into dedicated chips [86:43] , so we did a lot of that. Second, it [86:47] was a zero-to-one process. We handled [86:53] many things back then, including [86:55] bringing in designs, deciding which IPs [86:57] to buy, signing the first partnership [86:59] agreements with foundries, and [87:01] evaluating numerous factors—we really [87:04] did a lot. These weren't things someone [87:08] in a technical role was originally [87:10] supposed to do. So, for an individual, [87:12] it’s helpful for entrepreneurship; [87:14] I’d say yes. Mm. [87:16] Right, your career choices from the [87:17] beginning to the second stage have been [87:19] quite consistent, as you wanted to... [87:21] Go from zero to one, allow yourself to [87:23] take on a broader scope, and complete [87:25] tasks end-to-end—it feels like an [87:26] internal startup within a big company. [87:28] Ah yes, it’s actually internal [87:30] entrepreneurship within a large company [87:32] . Back then, AI wasn't as prevalent yet [87:35] , and the GPU wasn't necessarily meant [87:37] for AI chips; it could have been for [87:39] something else. So here, because I [87:45] enjoy doing it, every time I make a new [87:47] choice, I ask myself if I can learn [87:49] things I hadn't been exposed to before, [87:52] while also ensuring the compensation is [87:54] decent, right? And your scope might [88:00] grow larger. It’s also possible that [88:03] in a large company, more people will [88:05] join later, so you have to figure out [88:07] how to collaborate with everyone to get [88:09] the job done. But at the very least, [88:13] when we joined, we were in a fantastic [88:15] position, basically a founding team [88:17] working in an internal startup state. [88:20] Right. It seems you really enjoy the [88:23] process of being given a vague problem, [88:25] making it clear step by step, [88:27] ultimately forming a complete path, and [88:29] solving the issue. Yes, because those [88:34] of us in architecture want to find [88:36] certainty amidst uncertainty, start [88:38] from the definition of a task, and then [88:40] solve the problem. [88:42] That’s beautiful. I think in terms of [88:44] career development and choices, I [88:46] really should learn more from you. I [88:47] feel I share that same personality; I [88:49] like being able to define a problem and [88:51] slowly build something from zero to one [88:53] . I don’t like going from one to 100, [88:55] but I especially enjoy going from zero [88:57] to one. Yeah, actually, some of these [88:59] opportunities are quite rare. So, the [89:02] experience of building AI chips at a [89:04] major internet company is truly unique, [89:06] because the culture is very different [89:08] from traditional chip firms. The entire [89:13] process allows you to start from [89:15] scratch with a blank slate, which was [89:17] very helpful for my later [89:18] entrepreneurial journey. Yes. [89:21] Right, and then you went on to start [89:23] your own business, and [89:24] participated in two startups. [89:26] Yes. At the previous company, you were [89:29] the Chief Architect, [89:30] and at this current company, ZFOW, you [89:33] chose to be the CEO. [89:35] Mm. Why did you make that choice? [89:39] Because at the previous company, as [89:41] Chief Architect, my work was still [89:43] similar to what I did before, though I [89:45] did take on some new tasks. For example [89:51] , at my previous company, besides chip [89:54] architecture, I also worked on system [89:56] software, involving myself with R-time [89:58] teams, and also brought in some of the [90:00] capabilities we had built back at [90:02] Alibaba. For instance, how we cooperate [90:09] with design services, how we work with [90:11] system vendors, and how to find [90:13] partners. However, in my current [90:17] company, because AI infrastructure is [90:19] quite different from just doing chips [90:21] or just doing software. When making [90:25] chips, the business model is fixed. You [90:30] build the chip, and if it's competitive [90:32] in two years, you just follow the steps [90:34] to sell the chips, boards, and software [90:37] services. So the go-to-market is, how [90:41] should I put it, very certain. But for [90:44] AI infrastructure, the entire industry [90:47] changes extremely fast. For example, we [90:50] have built many products, but how do we [90:52] sell them? That is a question—how [90:55] exactly do you price them? What exactly [90:57] are you providing? And are you doing [91:00] consulting, or a service, or a [91:02] subscription? For me, this is a whole [91:05] new challenge. So I felt I had to take [91:10] this on myself, because it's hard to [91:12] find someone who can combine technical [91:14] innovation with business model [91:16] innovation. That’s why it’s another [91:21] learning process for me. Yes, mm. [91:25] Challenging yourself, playing the game [91:27] of life. [91:28] Right, it is quite challenging, because [91:30] selling chips and selling software are [91:32] really very different. Yes. So, you [91:34] went from being a Chief Architect to [91:37] becoming a CEO. [91:39] How much time have you spent on product [91:41] , sales, marketing, fundraising, and [91:43] technology during this past period? How [91:46] has your role shifted overall? [91:50] Uh, actually, I spend quite a lot of [91:52] time on product technology, but the [91:54] majority of my time is spent on BD. Yes [92:00] , finding partners, talking to [92:02] potential clients, signing MOUs, and [92:04] defining the business model together— [92:06] that part of the work takes up a huge [92:09] portion of my time. Secondly, our burn [92:13] rate is relatively very low. Currently, [92:18] fundraising does take up a share of my [92:20] energy, but I want to keep fundraising [92:22] within a very short window rather than [92:24] having it occupy my time long-term, yes [92:26] . So, my goal now is to spend more time [92:30] on business and BD. I spend most of my [92:32] time there, while still continuously [92:34] following up on product definition. I [92:36] have a solid understanding of basically [92:38] every technical detail, yes. [92:40] Right, so you spend a lot of time [92:42] talking to clients, [92:43] determining the business model, [92:44] defining the product form, [92:46] and after a while, waiting until these [92:47] are all clearly discussed, with clients [92:48] in place and a business model ready, [92:50] Yes, [92:51] you spend a month getting it all done [92:52] in one go and then dive in. Yes, [92:54] that’s my own personal model. Of [92:56] course, as I learn in the process of [92:59] being a CEO, perhaps some people are [93:01] constantly fundraising; by raising more [93:03] capital, you can do more things. But [93:06] for us in the chip industry, we might [93:09] prioritize making the business case [93:11] work first, having paying users, and [93:13] proving your value. Subsequent [93:16] fundraising, I feel, is just natural— [93:18] as long as it serves to satisfy your [93:20] business development. Once I have a [93:23] significant business, my fundraising [93:26] will actually be much faster, yes, hm. [93:28] Well, I’ve heard many successful [93:30] entrepreneurs in Silicon Valley say [93:32] that fundraising is just a natural [93:34] byproduct. Once you have a real [93:35] business, many investors don’t even [93:37] need you to ask; they’ll line up to [93:39] offer you money to help expand your [93:41] business. Ah, yes, because the logic of [93:43] fundraising is different from the logic [93:45] of building products and running a [93:47] business. Fundraising is a different [93:49] skillset. Yes, and if you spend too [93:51] much time on it, it really does affect [93:53] the time you have to actually run the [93:55] business, hm. [93:56] Hm. But fundraising ability is also [93:58] very important. [93:59] It is important. Some companies really [94:00] do rely on the CEO’s strong [94:01] fundraising ability to keep overcoming [94:02] obstacles and winning battles. [94:03] Exactly, exactly. [94:04] And having a strong exit capability, [94:05] being able to...Exactly, exactly, that [94:07] is also a very important skill, I... [94:08] Everyone has different ways of [94:09] competing in the marketplace. [94:10] Yes, no, and I’m also learning, [94:12] learning, learning. [94:13] Over the past period, your company [94:15] announced some inference optimizations [94:17] on the B200, right? A 1.5 x increase in [94:19] peak throughput and two to three times [94:21] that of... [94:22] tail latency improvements, right? That [94:24] is, P99 latency. [94:26] Yes. [94:26] How did you go about developing this [94:28] entire process? [94:30] Well, for this, we were actually there [94:32] at Day Zero, or very early on, [94:35] supporting DeepSeek-V 3 on 8x B200s [94:37] through the vLLM framework, and we [94:39] found certain configurations by using [94:42] some simulation methods. Then, we used [94:47] those configurations to set the [94:48] parameters for the vLLM framework. For [94:53] example, our conclusion for 8x B200s [94:56] was whether to use P-D separation or [94:58] not, how many GPUs to allocate for [95:01] Prefill, and how many for Decode. Those [95:08] decisions were reached through [95:09] simulation and then applied to [95:11] configure the vLLM runtime. But we also [95:17] did a lot of engineering work in [95:19] between, because getting a concurrent [95:21] vLLM runtime to run stably—and there [95:23] were many issues with throughput—was [95:25] a real challenge. Actually, the [95:30] open-source framework was also evolving [95:33] at the time, so our approach was to use [95:35] simulation to quickly identify these [95:37] configurations, and then......use those [95:40] configurations to integrate directly [95:42] with the vLLM framework to achieve a [95:44] more optimal deployment. That was the [95:47] whole logic and train of thought. [95:50] However, it actually took a lot of time [95:53] to get the framework stabilized, [95:54] because when DeepSeek first came out, [95:56] there were many bugs and quite a lot of [95:59] issues. Yes, yes. Regarding the process [96:02] you just mentioned, I've seen on social [96:04] media that everyone is saying these [96:06] open-source runtimes are too complex [96:08] and troublesome, and it takes so much [96:10] manpower and resources to get good [96:12] results. They surely must be aware of [96:14] this issue themselves. [96:16] So, comparing their internal [96:18] optimizations to yours...What is your [96:20] specific advantage here? [96:23] Actually, we are also considering [96:25] collaborating with the open-source [96:27] ecosystem. Because our simulation can [96:30] provide a virtual backend for these [96:32] ecosystems, your runtime can run in a [96:34] virtual simulation environment. This [96:37] way, you don't need as many GPUs to [96:39] perform these optimizations, and you [96:41] can even start them earlier. So I [96:45] believe we are complementary. In a [96:48] sense, this is also a tool to help with [96:50] design and optimization. [96:52] Exactly. Actually, many clients come to [96:56] us for architecture design exploration. [97:04] This tool is also very helpful for chip [97:06] design, especially for AI chips, [97:08] because the first step in chip design [97:10] is simulation, so this tool can be [97:12] considered an architectural EDA tool. [97:21] However, we don't just use this tool [97:23] for chip design assistance and [97:25] architecture exploration; it can also [97:27] be used for data center optimization. [97:32] Many chip companies are actually trying [97:34] this internally, providing some of [97:36] their internal simulators to those [97:38] doing model inference, allowing for [97:40] rapid iteration and optimization [97:42] strategies. Many chip companies are [97:46] doing this. But we are different [97:49] because we want to build a neutral [97:50] platform. Ours is compatible with [97:53] different chip architectures and [97:55] systems. You can combine A and B, for [97:59] example, NVIDIA hardware with AMD [98:01] hardware, or hardware from companies [98:03] other than NVIDIA, to perform [98:05] simulation optimization and eventually [98:07] achieve low-cost inference or training. [98:11] We want to create this kind of [98:13] universal, neutral, and impartial [98:15] platform. [98:17] Yes, in this way, there isn't so much [98:19] pressure to be tied to one vendor, and [98:21] anyone can use it. [98:23] Exactly, exactly. And the industry also [98:27] lacks such tools, tools that can really [98:30] help you explore and tune without [98:32] needing actual GPUs. [98:35] Well, those results you mentioned [98:37] earlier, the 1.5 x peak performance, [98:39] those results. Are they simulated or [98:41] real? [98:42] Those are real. We collaborated with [98:45] Neocloud; they provided the GPU [98:47] resources, and we did the tuning. [98:50] Was there a big difference between [98:51] those and your previous simulation [98:53] predictions? [98:54] Uh, for our DeepSeek model, it's [98:56] divided into stages. Currently, our [98:59] predictor can reach over 90%accuracy [99:01] for the prefill stage compared to [99:04] actual runtime, and for the decode [99:06] stage, it's roughly between 80%and 90%. [99:11] The reason is that there are some [99:13] dynamic behaviors during actual runtime [99:15] . Since it's dynamic, when you simulate [99:22] , you can only provide various [99:24] scenarios; it's very hard to simulate [99:26] precisely based on the specific data [99:29] distribution. So, we can achieve [99:34] simulation accuracy close to 90%, yes. [99:38] My understanding is, does this dynamic [99:40] refer to when user requests come in, [99:42] their arrival time, and the resulting [99:44] system load or temperature? [99:48] Yes, that dynamic includes things like [99:50] batching, concurrency dynamics, as well [99:53] as expert scheduling. In MOE models, [99:58] there is expert scheduling; when your [100:00] data distribution changes, the expert [100:02] routing changes, so there are many such [100:04] dynamic behaviors. These dynamic [100:08] behaviors are actually quite hard to [100:10] simulate. You can only simulate the [100:13] data distribution, or use results [100:15] obtained through profiling to calibrate [100:18] the simulation model. Therefore, for [100:22] our simulations, we are able to [100:24] calibrate our results using profiling [100:26] data. This makes us quite unique in the [100:31] industry; we are chip and architecture [100:33] designers who use this approach to [100:35] drive optimization. This is quite [100:39] interesting, but the problem is [100:41] actually very challenging: how do you [100:43] achieve enough simulation accuracy [100:45] while still being able to optimize? You [100:48] have to perform a lot of abstraction; [100:50] you need to abstract your system [100:52] architecture and your network [100:54] simulation, right? For example, if you [100:57] are doing distributed inference, you [100:59] need to simulate the network. Network [101:04] simulation involves network topology, [101:06] the precision level of switch [101:08] simulation, how to simulate routing, [101:10] whether to simulate congestion control [101:12] algorithms, and to what extent it is " [101:14] good enough" for optimization. Without [101:18] having truly built complex real-world [101:20] systems, and then being able to [101:22] abstract them into this framework, it [101:24] is actually very difficult to achieve; [101:26] the challenge is extremely high. [101:29] It feels like you are building a [101:31] virtual data center. Actually, people [101:34] have recently brought up something [101:37] called DSAL, or "AI Token Factory [101:39] Simulator," and we are somewhat similar [101:42] to that concept; yes, Jensen mentioned [101:44] this at GTC. Called AI Token Factory [101:47] Simulator, exactly. [101:48] This stuff is indeed too difficult. You [101:50] mentioned the congestion algorithm— [101:52] how to send, how to receive, [101:54] and how to route it, roughly referring [101:56] to that kind of architecture. [101:58] Exactly. [101:59] Yes. That will affect the results, but [102:02] the expert strategies in MOE will too, [102:04] right? [102:05] That will also have an impact. Well, [102:09] but in this regard, I’m confident we [102:11] can definitely build abstractions, [102:13] because AI workloads are relatively [102:15] more predictable compared to algorithms [102:18] running on general-purpose CPUs, so we [102:20] can achieve this abstraction. After [102:25] hearing your explanation, on the Ant [102:27] Group website, besides the AI [102:28] infrastructure optimization we just [102:30] discussed, [102:31] you’ve also built an Open Cloud [102:33] AutoTuner, [102:34] and a memory manager. Yes. [102:36] Actually, linking these three together, [102:38] the path you described earlier is [102:40] becoming clearer, right? [102:41] Exactly. [102:42] My understanding is that the Open Cloud [102:44] handles the upper-layer applications, [102:45] user requests, and interactions, while [102:47] the memory part looks at how to manage [102:49] video memory and RAM to optimize [102:51] computation—is that how you see it? [102:53] That’s exactly how you’re thinking [102:54] about it. Yes, these are actually two [102:56] levels of optimization. What we talked [102:59] about earlier was model serving [103:00] optimization, and this is agent-level [103:02] optimization. It’s really about how [103:07] to choose the model based on user [103:08] behavior, how to select memory [103:10] allocation, and how to perform optimal [103:12] configuration at the Open Cloud agent [103:14] level. The point we’ve always wanted [103:20] to make is that we already have many AI [103:22] chips, many open-source frameworks, and [103:24] many agent inferences, but the [103:26] configuration for every case is [103:28] different. If you need a large number [103:32] of engineers to handle these things, it [103:34] gets quite troublesome. So, what we [103:36] want to do—including the serving [103:38] AutoTuner and the agent inference [103:40] AutoTuner—is based on the same [103:42] concept: we want to use automated [103:44] optimization methods to get this done. [103:46] It seems like historically, there have [103:48] been many "auto" companies in the [103:50] database field too. You hit the nail on [103:52] the head; when we worked on database [103:54] queries, there was something called a " [103:56] query optimizer." [103:59] And a lot of what it did, for example, [104:02] deciding whether to use the CPU or [104:04] where to offload tasks, or how to [104:06] allocate memory—the complexity was [104:09] actually similar to, or even greater [104:11] than, AI, because databases have many [104:14] random, dynamic, and data-dependent [104:16] behaviors. While AI has things like MOE [104:22] and batching, most of it is still [104:24] matrix operations, so it’s relatively [104:26] fixed. So, as we move AI operations [104:30] toward the database approach, we’ll [104:32] see more of these random behaviors [104:34] being introduced. Therefore, when [104:37] building an optimizer, some of those [104:39] algorithms can indeed be similar. [104:42] But isn't commercialization quite [104:43] difficult? Because from what I [104:45] understand, companies that build [104:47] database optimizers...Hmm. ... [104:48] have there really been that many that [104:50] actually survived? [104:50] You are absolutely right; database [104:53] acceleration companies rarely succeed. [104:58] The reason is that their business [105:00] models evolve very quickly, and for [105:02] those of us in software, the technology [105:04] stack is so deep—for example, those [105:06] of us working on optimizers find it [105:08] very hard to keep up with these trends [105:10] when hardware is involved. Also, the [105:17] people building databases often have [105:19] their own optimizers, so it becomes [105:21] very difficult to define a viable [105:23] business model. [105:26] Mm. [105:27] Exactly, because several database [105:29] experts I previously admired, [105:30] started similar companies, and, uh, [105:33] they all ended up struggling quite a [105:34] bit. True, the technology is impressive [105:38] , but the business model—and this is [105:40] why I am also constantly learning—is [105:42] that for an AI infra company, you [105:44] either need to bring clients who need [105:47] and trust you, believing you can [105:49] deliver, or you bring the resources— [105:51] the GPU resources. You have to lean on [105:54] one of those two sides. Otherwise, it [105:56] is very difficult; companies purely [105:58] focused on inference or optimization [106:00] find it hard to secure their place. [106:03] Right. Right, many that appear to be AI [106:05] infra companies are actually GPU [106:07] companies, or— [106:07] Right, many, uh, many AI infra [106:09] companies are actually GPU companies, [106:11] or they are AI infra companies that are [106:13] tied to a specific client, right? [106:15] Right, strongly bound. Yes, strongly [106:18] bound to a major client. [106:19] Right. [106:20] So, you are aware of this history. [106:23] Mm. [106:24] So the challenges for this company are [106:26] indeed quite significant. The [106:29] challenges are immense—there are [106:31] technical challenges, and there are [106:33] commercialization challenges—but I [106:35] think this is a crucial problem, and if [106:37] solved, the value would be immense. The [106:41] industry also lacks a neutral [106:43] simulation platform that can perform [106:45] optimization. And things like serving [106:47] runtimes are missing a virtual backend. [106:50] There is so much to be done here. I can [106:53] see that if we move away from GPUs, [106:55] open-source communities or various [106:57] vendors could use your backend to [106:59] perform all kinds of operations. [107:02] Right. [107:03] It would save a significant amount of [107:04] time and effort. [107:05] Exactly. To put it bluntly, our company [107:09] could become the architecture team for [107:11] any AI infra or chip company, as we [107:13] have the tools and the talent, right? [107:15] Right, this type of model is actually [107:17] very easy to be acquired, you know? [107:19] After hearing your description. That is [107:21] also a possibility, yes. [107:22] Yeah, and there’s another company [107:24] that just came to mind while you were [107:25] describing that. [107:26] Mm, VMware. [107:27] Ah, yes. [107:28] Right, that company back then was also [107:29] ...in terms of commercial— [107:31] Commercialization was probably quite [107:32] difficult, too. [107:32] Yeah, but then it suddenly exploded, [107:34] because they did virtual machines. [107:35] Yes, exactly. [107:36] Right, you were doing these virtual [107:37] machines, doing all sorts of virtual [107:39] abstractions. [107:40] Yes. [107:40] Right, maybe at the beginning, no one [107:42] could see the business model clearly. [107:44] But then one day, suddenly every cloud [107:46] provider had to deploy this set of [107:48] things. Yes, I think from my [107:50] perspective, Jensen has already seen [107:52] this. That’s why he’s building this [107:56] AI Token Factory Simulator, because AI [107:58] hardware and system software are so [108:00] complex that nobody can handle them [108:02] anymore. And then there’s the [108:05] hardware cost; to really deploy a [108:07] system and then optimize it, what’s [108:09] actually missing isn't optimization [108:11] engineers, many AI infra companies lack [108:13] the resources, yeah. [108:15] Well, I think there is a lack of [108:17] engineers too, because the current [108:18] level of complexity is something [108:20] graduates just can't handle, you know? [108:22] Uh, yes, that’s right, that's right. [108:24] It's just too complex. I mean, for a [108:26] graduate to be able to handle it, [108:28] everyone I’ve seen is either someone [108:29] who has worked in the industry for many [108:31] years and knows the underlying GPU and [108:33] architecture, or someone who is heavily [108:34] involved in the SD or LLVM communities [108:36] and has learned a vast amount of [108:37] knowledge there. [108:38] But for anyone else, to expect them to [108:40] just jump in and start optimizing, [108:42] Based on my personal experience and [108:44] current interviews, it’s just not [108:46] possible, honestly. Our team's [108:48] experience is also quite unique. [108:51] Everyone here is a practitioner; [108:53] we’ve deployed systems on GPU clouds [108:55] and built full-stack GPU cloud [108:57] solutions for providers. And we have [109:01] experts, like my Ph.D. peer, who has [109:03] published at HOT Chips and worked on [109:05] simulators for many years. I have that [109:09] background too, always working on [109:11] software-hardware co-design for chips. [109:15] With this understanding, we are [109:17] essentially solving our own problem of [109:19] how to optimize and how to design the [109:21] architecture, yes. [109:22] So you are your own first batch of [109:24] customers. [109:25] Uh, yes, that’s right, exactly. [109:27] How did you pull this team together, [109:28] and how many people are there now? [109:30] Our core team is small, just a few [109:32] people, but many are former students or [109:35] colleagues—people who have that kind [109:37] of "comradeship" from working together [109:39] before. [109:41] Battle-hardened veterans of the chip [109:43] industry. Oh, right. [109:44] It’s so cool, so cool, I think. [109:46] Gosh, the experience and knowledge in [109:49] your brains is kind of priceless, [109:50] honestly, for real. [109:52] Mm. [109:52] We feel like the new generation of [109:54] young people. [109:54] Mm. [109:55] Those of us. [109:57] Having not fought the battles before, [109:59] even with using AI agents now, we don't [110:01] know how to extract the knowledge and [110:03] experience currently in your heads. [110:05] Don't know how to get it. [110:07] Uh, you're also right, some experience [110:09] is, for example. [110:11] Making mistakes. Right, it's about [110:14] learning from mistakes. Chips are so [110:16] expensive, so accumulating this [110:18] experience is actually very important. [110:21] Of course, because lately AI [110:22] infrastructure has become a bottleneck, [110:24] and chips have become a bottleneck, [110:26] which used to be the case for chips. [110:28] You know, in Silicon Valley, internet [110:31] companies actually pay much higher [110:33] salaries. Many of my friends from [110:36] before actually switched careers to [110:38] become coders. And those of us who have [110:41] stayed in the semiconductor industry [110:43] grinding away are actually quite few, [110:45] yes. Mm. [110:46] It’s quite fascinating; people might [110:47] not know that in Silicon Valley, the [110:49] pay for chip engineers is much, much [110:50] lower than in the software industry. [110:52] A lot lower, yes. Why is that? [110:54] That is, this is a question of capital [110:57] operation, right? Chip company costs [111:01] come from fixed asset investment, like [111:04] hardware investment, tape-out costs, [111:06] EDA software license fees, or IP costs, [111:09] so human capital is secondary. Of [111:15] course, the top-tier companies are few, [111:17] but most people are actually engineers [111:19] using EDA tools, so their pay isn't [111:21] high. And for internet companies, a [111:27] large part of their costs—before AI, [111:30] infrastructure, or GPU setups—were [111:32] mostly invested in human resources. [111:37] Once you produce this software, you can [111:39] scale at zero marginal cost. But the [111:44] situation is changing a bit now. Now [111:48] these cloud companies have become a bit [111:50] like our traditional semiconductor [111:52] companies; their fixed capital [111:53] investment has become the main cost, [111:55] and people might actually be replaced [111:58] by AI. It's a bit like the internet [112:01] industry or hyperscalers shifting [112:03] toward how we view traditional [112:04] semiconductor companies. CAPEX has [112:09] become the largest investment, and your [112:11] revenue cost is proportional to your [112:13] CAPEX, rather than being able to scale [112:16] infinitely through the replication of [112:18] capabilities. [112:21] It really feels like, if we look at the [112:23] entire training pipeline for large [112:25] models—from pre-training to [112:27] fine-tuning and then to RL— [112:29] Yes, [112:30] Once that whole chain is built, [112:31] Mm. [112:32] The value of humans is becoming lower [112:34] and lower, meaning that now large [112:35] models are assisting humans in managing [112:37] the entire training pipeline. Right, [112:39] right. [112:39] For an individual, a fresh graduate, [112:41] Yes. [112:42] The large model guides them to perform [112:44] certain operations. [112:45] Right. I feel that you can think of [112:48] large models—using the semiconductor [112:50] industry as an analogy—as your EDA [112:52] tools. And more of our engineers, [112:55] software engineers, are becoming users [112:57] of these EDA tools. So, these big [113:01] companies are investing more in [113:03] infrastructure. Everyone might need to [113:09] accept that the top tier—a bit like [113:11] the architects in our chip industry— [113:14] can still maintain very good income or [113:16] returns, but the average engineer has [113:18] become a software engineer using AI [113:20] tools. There will definitely be some [113:25] changes in this mindset. Mm. For some [113:28] high-level roles, on one hand, these [113:30] skills are indeed scarce, and for [113:32] reasons like maintaining a leading [113:34] position, yes, [113:35] But once we enter a period of stable [113:37] development, [113:38] Right. [113:38] It's hard to imagine that companies [113:40] will still be paying such high salaries [113:42] as they are now for all sorts of roles. [113:44] Well, actually, such high salaries are [113:46] only for a very small portion of people [113:48] . People might see sensationalized [113:51] reports in the newspapers, but most... [113:53] You can think of it as an analogy to [113:55] architects in the chip industry; they [113:57] are, well, everyone knows these people [113:59] are just the core, right? [114:00] Exactly, exactly, exactly. Mm. [114:03] Oh boy. Faced with such a future [114:06] outlook, [114:08] Mm. [114:08] Do you think high school students [114:10] should still study computer science, or [114:12] still get into chip-related fields? [114:14] Uh, I think they should. It's still [114:16] needed, still needed. Everyone needs to [114:18] become an architect. Put simply, it [114:20] means you can bridge the gap from top [114:22] to bottom and use tools to help you [114:24] realize many things. So, the [114:25] requirements for people are actually [114:27] very high; you still need to learn the [114:30] underlying fundamentals. So you still [114:33] need computer science, you need to [114:35] learn business models, or business in [114:37] general, and you also have your own [114:39] tech knowledge to pick up. I mean, [114:44] everyone really should have this kind [114:46] of architect mindset, whether it's for [114:47] choosing a career or for your [114:49] professional training. Right, yeah. [114:53] Looking at it from another angle, if [114:55] your interest isn't that strong, maybe [114:57] you don't need to be so obsessed with [114:59] it. If you’re really interested, [115:00] then you should go for it. [115:01] Right. [115:02] But if you're not interested, [115:03] Yeah. [115:04] The process of becoming a top-tier [115:05] architect is quite grueling, I think. [115:08] That's true. If it’s not your passion [115:10] , I still think productivity will see a [115:13] massive boost later on. AI can enhance [115:16] productivity; you could become someone [115:18] like us in the semiconductor industry [115:20] who uses AI. You might not get top-tier [115:24] pay, but that boost in productivity can [115:26] ensure basic welfare for everyone. [115:28] Exactly, you'd at least have no worries [115:31] , living a happy life every day. Even [115:33] if the salary for an ordinary [115:35] semiconductor engineer isn't that high, [115:37] you can still maintain a decent life [115:39] without much overtime or toxic [115:41] competition. [115:42] That sounds like a pretty good thing, [115:44] doesn't it? [115:45] Well, to some extent it is, but I think [115:48] society might eventually become [115:49] polarized, and many people might not [115:52] even need to work. [115:54] I feel like I had a bit too much fun [115:56] chatting with Mr. Zhibing today. A lot [115:58] of this content wasn't prepared; Mr. [116:00] Zhibing provided such a massive amount [116:02] of information that I had to improvise [116:05] everything. I tried my best to help [116:07] everyone clear up the last 20 years, [116:09] Mr. Zhibing's history in the chip [116:11] industry, and I hope we helped everyone [116:13] sort out how many generations of [116:15] updates the chip industry, especially [116:17] here in Silicon Valley, has gone [116:19] through over the last 20-plus years. [116:21] Yes, and I'm also very grateful for [116:23] Uncle Moon's invitation. I might have [116:26] spoken a bit fast, but we could [116:28] actually talk about each of these [116:30] topics for several more hours. [116:32] How about you come on the show more [116:34] often? For this time, we’ll just [116:35] start by setting the stage, and then we [116:37] can go through each chapter in detail [116:39] later, okay? [116:40] Thank you everyone, thank you everyone, [116:42] and thank you, Mr. Zhibing.