AMD reveals the MI325X, a 288GB AI accelerator built to battle Nvidia's H200

House of Zen hopes to catch its AI rival by moving to a yearly release cadence

An uncertain future for MI300A

While we've touched on AMD's AI-focused GPU, it seems that the APU variant won't be getting the same HBM3e treatment – at least not yet.

That chip – the heart behind the upcoming El Capitan supercomputer – swaps out two of the GPU dies in favor of a trio of Epyc core complex dies (CCDs) for a total of 24 cores.

The novel architecture allows the CPU cores to share memory directly with the GPU, speeding up data intensive tasks by eliminating copy penalties associated with having to move data between the two.

Speaking with press ahead of Computex, Andrew Dieckmann, CVP of AMD's Instinct product line, waffled on the roadmap for future MI400/500A parts. "We continue to see really strong interest in traction for MI300A, particularly in the kind of traditional HPC use cases," he said. "There are certain attributes of the single-package APU which are very attractive, and we will continue to evolve certain attributes of that product line as we move forward. We're not going to talk about specifics around exactly what a 400-class of product or 500-class of product, from an APU perspective, would look like, but you can expect to see continued innovation from us in that area."

Assuming AMD hasn't lost its appetite for the HPC sphere or converged CPU-GPU architectures, it may simply be down to future chips relying on yet unreleased CPU cores.

MI300A is in a category of its own. Nvidia's Grace Hopper and Grace Blackwell superchips are a different beast entirely – they don't share memory and don't rely nearly as much on advanced packaging. Intel's Falcon Shores XPUs, meanwhile, were originally slated to co-package CPUs and GPUs just like AMD's MI300A, but were eventually ditched in favor of a Habana-Gaudi-plus-Xe Graphics processor.

Still no PCIe cards

Notably missing from AMD's MI300-series lineup is a PCIe card form factor. As it stands, the more than two-year-old MI210 is still AMD's most sophisticated CDNA card available in a PCIe form factor.

According to AMD, that won't be changing with the introduction of MI325X. "We are not, today or at Computex, going to be announcing specifics around a PCE form factor," Dieckmann conceded, adding that the PCIe form factor continues to see market interest.

So, AMD isn't ruling out the possibility of a high-end PCIe card. However, if the MI210 does eventually get a successor it may not be CDNA based.

Over the past few months, AMD has been working to build support for its ROCm accelerated computing framework – most notably by making it available to those running certain 7000-series gaming and workstation cards.

If we had to guess, future PCIe cards targeting AI inferencing will run on the RDNA architecture used in its consumer and workstation cards.

Su and Co wouldn't be the first to go down this route. Nvidia has employed multiple distinct architectures for its high-end datacenter chips and mainstream accelerators on multiple occasions over the years. Its L40, A6000 Ada Generation workstation cards, and consumer-focused RTX 4090 share the same Ada Lovelace-based GPU die, though features do vary by SKU. Meanwhile, Nvidia's 100 and 800-series parts use its Hopper architecture.

So, it wouldn't be surprising to see AMD push its RDNA graphics more aggressively in the datacenter moving forward.

If it doesn't, however, it could be the opportunity that Qualcomm and its friends Cerebras and Ampere have been waiting for. While Qualcomm may not be the first name you think of when it comes to datacenter compute, it's actually had PCIe-based AI accelerators aimed at inferencing on the market for years.

It's also potentially good news for Intel – which also plans to offer PCIe-based versions of its Guadi3 accelerators later this year. ®

Also at Computex: AMD previews Turin Epyc CPUs, expands Instinct GPU roadmap and We're the Ryzen force in CPUs for AI PCs, says AMD.