AMD Instinct MI300 Could Feature Quad MCM GPUs Based on CDNA 3 Architecture


AMD is about to launch its Instinct MI200 GPU accelerator which will be the first chip to feature an MCM graphics architecture but it looks like the next-generation Instinct MI300, featuring the CDNA 3 architecture, is going to blow it away with a quad MCM design.

AMD Instinct MI300 Rumored To Feature Four MCM GPUs Based on CDNA 3 Graphics Architecture

The AMD Instinct MI200 accelerator with its CDNA 2 architecture is expected to feature two GPU dies on the same package. These will be connected by an Infinity Fabric interconnect and will also feature a separate die that will serve as a multi-tier cache between the two GPUs. Each graphics die will be known as GCD while the cache-die will be known as MCD.

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There will be two CDNA 2 GPUs onboard the Instinct MI200 package but the next-generation HPC accelerator is rumored to double that. According to Kepler_L2, the Instinct MI300 will feature a 4-GCD design based on the brand new CDNA 3 architecture. The upcoming Instinct MI200 was going to feature 128 compute units per die but that has changed to 110 compute units since last week's rumor. A total of 220 Compute Units would net 14,080 cores and if we take the exact number and multiply it by 4 (the number of GCDs on Instinct MI300), we end up with 440 Compute Units or an insane 28,160 cores.

A recent AMD ROCm Developer Tools update that was spotted by Komachi did confirm a maximum of 4 MCM GPUs but those are simply 'Aldebaran' SKUs. There are expected to be at least four CDNA 2 powered Instinct accelerators with their respective (unique IDs) listed below. Note that the number doesn't represent the number of dies on each device but rather the device itself:

  • 0x7408
  • 0x740C
  • 0x740F
  • 0x7410

Now that would be true if AMD makes no changes whatsoever when moving from CDNA 2 to CDNA 3 but that's not the case. CDNA 3 is expected to bring forward a revised new architecture that won't be another Vega derivative like Arcturus or Aldebaran. The GPU architecture may also use a layout that might end up looking similar to the new WGP/SE arrangement on the new RDNA 3 chips or an entirely new design tailored towards the HPC segment. But one thing is for sure, those quad-MCM GPUs definitely are something that we can't wait to see in action!

AMD Radeon Instinct Accelerators 2020

Accelerator NameAMD Radeon Instinct MI6AMD Radeon Instinct MI8AMD Radeon Instinct MI25AMD Radeon Instinct MI50AMD Radeon Instinct MI60AMD Instinct MI100AMD Instinct MI200AMD Instinct MI300
GPU ArchitecturePolaris 10Fiji XTVega 10Vega 20Vega 20Arcturus (CDNA 1)Aldebaran (CDNA 2)TBA (CDNA 3)
GPU Process Node14nm FinFET28nm14nm FinFET7nm FinFET7nm FinFET7nm FinFETAdvanced Process NodeAdvanced Process Node
GPU Dies1 (Monolithic)1 (Monolithic)1 (Monolithic)1 (Monolithic)1 (Monolithic)1 (Monolithic)2 (MCM)4 (MCM)?
GPU Cores23044096409638404096768014,080?28,160?
GPU Clock Speed1237 MHz1000 MHz1500 MHz1725 MHz1800 MHz~1500 MHzTBATBA
FP16 Compute5.7 TFLOPs8.2 TFLOPs24.6 TFLOPs26.5 TFLOPs29.5 TFLOPs185 TFLOPsTBATBA
FP32 Compute5.7 TFLOPs8.2 TFLOPs12.3 TFLOPs13.3 TFLOPs14.7 TFLOPs23.1 TFLOPsTBATBA
FP64 Compute384 GFLOPs512 GFLOPs768 GFLOPs6.6 TFLOPs7.4 TFLOPs11.5 TFLOPsTBATBA
Memory Clock1750 MHz500 MHz945 MHz1000 MHz1000 MHz1200 MHzTBATBA
Memory Bus256-bit bus4096-bit bus2048-bit bus4096-bit bus4096-bit bus4096-bit bus8192-bitTBA
Memory Bandwidth224 GB/s512 GB/s484 GB/s1 TB/s1 TB/s1.23 TB/s~2 TB/s?TBA
Form FactorSingle Slot, Full LengthDual Slot, Half LengthDual Slot, Full LengthDual Slot, Full LengthDual Slot, Full LengthDual Slot, Full LengthDual Slot, Full Length / OAMTBA
CoolingPassive CoolingPassive CoolingPassive CoolingPassive CoolingPassive CoolingPassive CoolingPassive CoolingTBA