In modern AI servers, PCIe switches are commonplace in architectures as GPUs and AI accelerators need direct access to local storage, networking, the host CPUs, and even other GPUs. Years ago, a company called PLX was acquired by Avago and it is now part of the Broadcom family. For the last decade or so, PLX-based PEX PCIe switches have been the industry standard for GPU servers, storage servers, and more. Even back in 2016-2017, we reviewed GPU servers with Broadcom switches. Now, the Astera Labs Scorpio line of PCIe switches is taking aim at Broadcom with a focus on the AI market.
New Astera Labs Scorpio PCIe Switch Targeting Broadcom in AI Servers
Astera Labs has two families. The Astera Labs Scorpio P-series is effectively a 4x 16-lane PCIe switch designed to connect four devices. The CPU, the GPU, a NIC, and NVMe storage.
The topologies have evolved over time but compared with previous generations, we are seeing a need for more PCIe devices in a single server, especially as NIC to GPU ratios have trended towards 1:1.
This configuration is used in many AI servers, and currently we see large Broadcom PCIe switches used in the boxes.
With the Scorpio P-series, Astera Labs hopes to have a smaller piece of silicon that handles that CPU-GPU-NIC-SSD connectivity, and we are likely to see these eight deployed on a server. Astera’s bet is that by providing fewer ports and a smaller switch, it will decrease complexity and make its switches highly competitive versus typical Broadcom switches that are around twice the lane count.
Likewise, the Astera Labs X-Series is designed to be the higher port-count version. Astera Labs is focusing sales directly to large customers, so it did not disclose a port count. The Astera Labs X-Series seems to be more for GPU-to-GPU configurations.
PCIe switches have been common in in both PCIe and OAM/ SXM architectures for a long time as well. Enabling Peer-to-Peer (P2P) communication across PCIe switches was a major achievement in AI as it allowed GPUs to communicate directly over the PCIe switch instead of through the host CPU.
Final Words
We were told that the Astera Labs Scorpio PCIe switches are sampling, and we were able to get actual photos of the devices. Our best sense is that they will hit the market in 2025, but these are certainly a step beyond just an idea. For Broadcom, this is another multi-billion dollar market that Astera Labs is pushing into.
