That title may be a bit challenging, but it is valid. With the UK-based Isambard 3 supercomputer NVIDIA Grace will have a 2.7PF supercomputer that NVIDIA is pointing out will be one of the three greenest. It is using non-accelerated for the three greenest claim. Perhaps the bigger part of this announcement is that it is a vote of confidence for Grace.
NVIDIA Notches a Modest Grace Superchip Win at ISC 2023
Isambard 3 is set to have 384 Arm-based NVIDIA Grace CPU Superchips. Since we would expect each to be ~144 cores each (2x 72 chip halves unless there is a different configuration for yield reasons) that will put the core count at over 55,000 cores. That FP64 performance is set to occur in under 270kW of power. We will note that smaller systems tend to perform better on an efficiency metric because they have smaller network radix. Still, that is around 700W/super chip all-in with networking.
For those who need a quick refresher, here are the key specs of the NVIDIA Grace CPU Superchip (2x 72 core chips) and the Grace Hopper which is 1x 72 core chip and 1x NVIDIA H100. Memory and interconnect are integrated into each.
These chips also use the Arm Neoverse V2 cores which is Arm’s high-performance core compared to the N-series scale-out cores we often see on cloud instances. The recent AmpereOne with 192 Cores may sound like significantly more, but the V2 cores of Grace should be much faster and with more memory bandwidth. We have not tested Grace yet, but if NVIDIA is not faster than Ampere’s cloud cores, then Grace is in trouble and we doubt it would be winning CPU-only machines.
Some folks have wondered why we have not seen more NVIDIA Grace in the market. My personal belief is that NVIDIA has been working on the platform and we will see more in the coming weeks. Many market commentators discuss per-core performance differences or that building an Arm chip is as easy as getting an Arm license. Many folks underestimate how much is required to have a platform that supports a diverse set of configurations that are required to be sold in OEM systems. That work is where Ampere did a better job than Cavium/ Marvell ThunderX(2), albeit with a more mature underlying ecosystem.
Hopefully, we get to show you these in more detail soon as they are one of our most anticipated CPUs of 2023.