Apple Silicon|Intel

AMD Instinct MI300 accelerator might have an Exascale APU mode

Please note that this post is tagged as a rumor .

AMD MI300 might be the start of high-performance APUs

A new leak puts a new socket name alongside MI300 and Zen4 CPU socket.

ExecutableFix discovered a new socket name “SH5” which is internally called MI300. This name is likely referring to the Instinct MI300 accelerator, a successor to MI200 which has not yet been released. The MI300 is now rumored to feature 4 GPU chipsets, a double of what MI200 is said to offer.

The leaker claims that SH5 refers to a Zen4 socket, which likely means that MI300 might have a Zen4 CPU chiplet on the same package, or at least some of its variants might.

There's a server socket called "SH5" that features CPU with CPUID 0xA80F00… called "MI300"

— ExecutableFix (@ExecuFix) September 16, 2021

As others have put it, the MI300 is not expected to launch for at least another year, which makes all those early rumors almost impossible to confirm at this point. It is, however, interesting to see what AMD is focusing on in the relatively near future.

This is not the first time are hearing about exascale APUs. In a paper “Design and Analysis of an APU for Exascale Computing” AMD has revealed a proposed design of such a high-performance design, featuring stacked HBM memory on top of GPU chiplets which would be combined with CPU chiplets.

It is also worth noting that back in 2019, so nearly 2 years ago, known leaker Komachi discovered the first traces of AMD MI200 Big APU mode. In this case, however, it might mean something else, such as a number of GPUs working in tandem with attached EPYC CPUs.

What is BIG APU Mode for MI200?🤔

— 遠坂小町@Komachi (@KOMACHI_ENSAKA) December 26, 2019

AMD Instinct Accelerators
Accelerator NameAMD Radeon Instinct MI60AMD Instinct MI100AMD Instinct MI200AMD Instinct MI300
Architecture7nm GCN5 (GFX906)7nm CDNA1 (GFX908)CDNA2 (GFX90A) CDNA3 (?)
CPU Zen4 (?)
GPUVega 20ArcturusAldebaran (MCM) ? (MCM)
Compute Tiles112 4
Compute Units64 (64)1202x 110 or 2x 55 4x (?)
FP32 Cores (Full GPU)4096 (4096)7680 (8192) TBC 4x (?)
GPU Clock Speed1800 MHz~1500 MHz TBC TBC
FP16 Compute29.5 TFLOPS185 TFLOPS TBC TBC
FP32 Compute14.7 TFLOPS23.1 TFLOPS TBC TBC
FP64 Compute7.4 TFLOPS11.5 TFLOPS TBC TBC
VRAM32 GB HBM232 GB HBM2128 GB HBM2E TBC
Memory Clock1000 MHz1200 MHz TBC TBC
Memory Bus4096-bit4096-bit TBC TBC
Memory Bandwidth1 TB/s1.23 TB/s TBC TBC
Form FactorDual Slot, Full LengthDual Slot, Full LengthOAM TBC
CoolingPassive CoolingPassive Cooling TBC TBC
TDP300W300W TBC TBC