AMD EPYC Milan Review Part 2: Testing 8 to 64 Cores in a Production Platform

[rbanffy]

https://www.anandtech.com/show/16778/amd-epyc-milan-review-part-2

[tyingq]

Benchmarks and price/performance are going to start getting confusing now that cloud providers are selling a mix of vCPUs where some are real cores, and some are hyperthreads. Amazon's Graviton instances are full cores. I expected that since ARM doesn't have hyperthreads. But now Google is selling EPYC full cores as vCPUs with Tau. I would guess that forces the other providers to follow suit.

[MR4D → tyingq]

If we’re lucky, we’ll end up where we need to be - performance per dollar.

But that’s probably a big “if”.

[nine_k → MR4D]

Performance is hard to measure as a scalar.

[fulafel → tyingq]

Terminology nit: s/hyperthread/SMT thread/ - HyperThreading is an Intel marketing name for their implementation of SMT.

[mhh__ → tyingq]

There are a few ARM CPUs that do SMT

[rbanffy → mhh__]

True, but I suspect that the simpler instruction format makes it much easier to extract parallelism from a single thread than it is with x86's.

[bserge → tyingq]

I was under the impression that was already the case with all Intel processors.

[tyingq → bserge]

Not from what I see. A vcpu is a hyperthread for most Intel instances.

[merb → tyingq]

actually only the tau instace type is marked as non smt. e2 use ht and smt.

tau is just a different more native workload.

[jccalhoun]

I was curious about the Altra processor listed in the charts since I hadn't heard of it. It is an Arm processor and it is absolutely huge - even bigger than the Epyc chip. https://www.anandtech.com/show/16315/the-ampere-altra-review

[tyingq → jccalhoun]

You might also like the Fujitsu A64FX. 48 cores. 60mm square package, so almost as large as the Altra, which is 77mm x 66.8mm.

https://www.fujitsu.com/global/products/computing/servers/su...

[rhn_mk1 → tyingq]

77mm×66.8mm comes out to 5144mm², so 60mm² sounds positively minuscule. Where's the mistake?

[errantblaze → rhn_mk1]

"60mm square package", I read that as 60mm×60mm.