At this point in the history of datacenter systems, there can be no higher praise than to be chosen by Nvidia as a component supplier for its AI systems.

Which is why upstart interconnect chip maker Astera Labs, which is taking on the likes of Broadcom and Marvell for PCI-Express switches, PCI-Express retimers, and CXL memory controllers, was quite pleased with itself when Nvidia gave its blessing to have upcoming server nodes using “Blackwell” GPU accelerators uses its PCI-Express 6.0 switches and retimers to link X86 GPUs to its Blackwell GPUs and in some cases network interface cards and storage as well.

The MGX is a set of server reference designs that comprise the basic building blocks of Nvidia’s own AI beasts and the clones of them that OEMs and ODMs create so they can get a piece of the action.

At the GPU Technical Conference 2025 last week, Astera Labs did two things. First, it demonstrated the interoperability of its “Scorpio” P-Series PCI-Express 6.0 fabric switches and “Aries” PCI-Express 6.0 retimers with Nvidia’s “Hopper” H100 and H200 GPUs as well as various Blackwell B100 and B200 GPUs used in HGX setups (the familiar two CPU by eight GPU designs that are now called HGX NVL8 for Hoppers and DGX NVL16 for Blackwells. Second, Astera was showing off an inference server designed by ODM server maker Wistron that was based on Hopper GPUs and that used its switches and retimers to link components together.

It is not at all clear where Nvidia itself is using Astera chips in its systems, and we are really just using this announcement as an opportunity to look into what Astera is offering, but Andrew Bell, vice president of hardware engineering at Nvidia did say in a statement that the Scorpio switches integrated with the “Blackwell-based MGX platform,” so there you have it. The Aries retimers, which are based on DSPs were not mentioned by name, but if you need to extend a PCI-Express 5.0 or 6.0 link to space components out a bit, you need these things, too.

Conceptually, this is how it all looks:

In the center of that chart above, the fabric can be any PCI-Express switch, but Astera would no doubt prefer it to be own of its own Scorpio switches, which it shows as well. Using switches and retimers from two different vendors is probably asking for trouble.

As you can see, you can use the retimers to link a GPU to a network or storage fabric as well as to a different PCI-Express fabric that is used to lash the GPUs directly to each other, much