Giant AMD APU at SC23 Discover the AMD MI300A and MI300X

At SC23 we saw a number of next-generation AMD systems. While we know that HPE-Cray and AMD are installing El Capitan, a 2-exaflop supercomputer, we also learned this week that Microsoft is rolling out a large number of AMD’s MI300X GPUs. We figured people might want to see the new high-end GPUs and APUs, so we took a few photos.

AMD MI300 Summary

For those who need a quick refresher, the AMD Instinct MI300 family is a modular architecture in which AMD combines GPU, CPU, HBM and more in a 3D stacked package. AMD can vary GPU and CPU tiles to achieve different types of configurations. Since AI is selling like hotcakes right now, the two most popular configurations we’ll likely hear about in the near future are the MI300A which is a quarter CPU and three quarters GPU, and the MI300X which is made entirely of GPUs.

At SC23 we saw both.

AMD Instinct MI300A at SC23

The first is the AMD Instinct MI300A. This is a large APU that we took a photo of back in June, but for some reason the dimensions weren’t recorded.

We saw the APU at the show in the Gigabyte G383-R80. We can see that it is a socketed processor.

The socket looks very familiar even though it is labeled “SH5”.

Forget DDR5 for a moment. The AMD MI300A’s SH5 socket is very similar to the SP5 socket for Genoa, Genoa-X and Bergamo.

Indeed, these even use the same style of bracket that we see in AMD’s mainstream server processors today.

The support is gray much like the AMD EPYC Milan-X.

Our Genoa-X samples had orange brackets like Genoa (the green is Bergamo.) Maybe gray is AMD’s color for its high-end HPC processors?

These were installed in the LGA6096 sockets of a Gigabyte G383-R80. It will be remembered that the SP5 socket for the AMD EPYC Genoa, Genoa-X and Bergamo is also an LGA6096 design. Four of these sockets were on the motherboard.

What interests us most is the CXL support. These chips do not have DIMM slots and instead use an integrated HBM for memory needs, much like the Intel Xeon MAX 9480, except with more capacity and primarily as an accelerator. The chips have multiple PCIe Gen5 interfaces. Ahead of AMD’s June 2023 data center event, we heard from people interested in expanding memory via CXL Type 3 devices to get more memory capacity. AMD still hasn’t clarified whether this is a supported feature.

AMD also had the MI300X at SC23, so let’s get back to that next.