Re:Cray, AMD to Extend DOE’s Exascale Frontier
by jacobush on Wednesday May 08, 2019 @09:24AM
(#19858568)
Which system are you referring to here?
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Re:Cray, AMD to Extend DOE’s Exascale Frontier
by wahern on Thursday May 09, 2019 @02:02AM
(#19865781)
From the article,
> Single-socket nodes will consist of one CPU and four GPUs, connected by AMD’s custom high bandwidth, low latency coherent Infinity fabric.
The article, at least, only describes coherency in the context of single-socket nodes. I suppose it's ambiguous whether Infinity fabric only connects components on the node or connects nodes to each other, but in fact Infinity fabric is the interconnect used with Zen CPUs, so I think it's pretty clear that in this case it only connects and provides memory coherency for 1xCPU and 4xGPUs.
Performant memory coherency across nodes would be quite an achievement, but not one they seem to have achieved. Rather, it seems they've simply revived the PS4 model.