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The Exiled · 20.11.2024., 10:18

Citiraj:

AMD crafts custom EPYC CPU with HBM3 memory for Microsoft Azure – CPU with 88 Zen 4 cores and 450GB of HBM3

Citiraj:

The custom AMD CPU used for HBv5 VMs leverages HBM3, usually the memory of choice for the latest data center-class GPUs, such as AMD’s MI300X. With a bandwidth of 6.9TB/s from four of the chips in a single VM, the VMs are almost nine times faster than the Genoa-X CPUs that Microsoft offers in HBv4 VMs, and nearly 20 times faster than Milan-X chips in HBv3 VMs. When paired with a CPU, the HBM3 fulfills a similar role as 3D V-Cache. Still, instead of expanding the pool of L3 cache, it effectively adds a massive L4 cache with even greater bandwidth and presumably much worse latency. However, the latter isn't as important in certain types of workloads.

Unlike Intel with the Xeon Max CPUs, AMD has not yet had an EPYC processor with HBM. The Azure HBv5 VM should be able to offer 6.9 TB/s of storage bandwidth. However, this does not consist of just one processor; Microsoft specifies 352 Zen 4 cores with a clock speed of up to 4 GHz. Each core should have up to 9 GB available and the mentioned 6.9 TB/s will be achieved in the STREAM Triad on 400 to 450 GB of HBM3. SMT is disabled and there is only one VM per server, so multiple VMs do not have to share the hardware. Apparently the EPYC processors with HBM were in development at AMD as Instinct MI300C. The model name is EPYC 9v64H.

Izvor: Tom's Hardware, ComputerBase i HardwareLUXX