Posts

BWR Episode 5: Celestial AI, More NVLink, and Merchant TPUs

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The Byrne-Wheeler Report Episode 5 is now available. In this episode: Marvell Technology has announced the acquisition of Celestial AI, a move that positions Marvell as a leader in next-generation co-packaged optics (CPO). Unlike traditional CPO focused on standards compliance, this deal targets the bleeding edge of scale-up interconnects for AI accelerators. In a surprising shift at AWS re:Invent, Amazon disclosed that its upcoming Trainium 4 AI accelerator will support NVLink Fusion. While Amazon typically relies on its proprietary NeuronLink, this move allows for a cookie-cutter rack design. AWS will be able to mix and match Nvidia GPUs and Trainium chips within the same physical infrastructure, speeding up deployment velocity. Reports indicate a massive shift in Google’s strategy: the company may be moving from strictly using TPUs for its own cloud services to acting as a merchant silicon supplier. Rumors suggest Meta is planning to deploy its own on-premise TPU cluster. Please exc...

Decoding Nvidia's Rubin Networking Math

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At GTC DC last month, Jensen Huang showed off components of the Vera Rubin NVL144 platform. First, here's the latest roadmap, which now includes BlueField-4 and BlueField-5. For more on that, see BWR Episode 4 .  Source: Nvidia Below is the Vera Rubin compute tray, which includes four Rubin GPUs. By GPU, we mean package not die. Note that the Blackwell NVL72 and Rubin NVL144 both have 72 GPU packages, but the NVL144 moniker denotes Nvidia's new math counting die. The company didn't rename the Blackwell configuration, even though that GPU also has two die. Each compute tray has two Vera CPUs, which are 88-core Arm processors. Two GPUs connect with one CPU using NVLink-C2C, a coherent variant of NVLink. Although the roadmap above shows CX9 as 1600G, each ConnectX-9 is actually 800Gbps, requiring eight chips to deliver the aggregate 800GB/s quoted for the tray. That means each GPU has a pair of 800G Ethernet/InfiniBand NICs for scale-out networking. Finally, a single BlueField...

BWR Episode 4, BlueField Rises

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 The Byrne-Wheeler Report Episode 4 discusses the RISC-V Summit NA, BlueField-4, SambaNova, and AWS Rainier. You can skip to 12:12 if you're uninterested in RISC-V.

LightCounting Publishes October 2025 Ethernet, InfiniBand, and Optical Switches for Cloud Data Centers Report

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October was a busy month, between the OCP Global Summit and being the lead author on the LightCounting switch report. The new report adds another level of granularity to the scale-up switch forecast, which incorporates NVLink, UALink, Scale-Up Ethernet (SUE), and non-Nvidia proprietary interconnects. There are many other changes to the report, including revisions to the methodology for the co-packaged optics (CPO) forecast. The newsletter summary is freely available: Co-packaged Optics Grow the Scale-out Switch Pie Source: Wheeler's Network

The Byrne-Wheeler Report for October 19, 2025

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In Episode 3, Joe and Bob discuss OCP-related announcements and the AMD-OpenAI deal. 00:00:26 OCP recap 00:01 AMD Helios rack 00:06:46 Broadcom Thor Ultra 00:12:32 Intel Crescent Island 00:19:11 AMD-OpenAI deal 00:26:33 Signing off

The Byrne-Wheeler Report for September 30, 2025

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 In case you missed it, Episode 2 of The Byrne-Wheeler Report is available. In this episode, Joe and I discuss the Intel-Nvidia deal, the Nvidia-Enfabrica combination, and Upscale AI's launch.

Introducing The Byrne-Wheeler Report

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My colleague Joe Byrne and I launched a video podcast covering the latest news in the chip world. Episode 1 covers Hot Interconnects and Hot Chips news from August as well as Arm's Lumex announcement and Nvidia's Rubin CPX. We hope you enjoy this new format, which will complement our respective blogs.