[Beowulf] Register article on Epyc

Bill Broadley bill at cse.ucdavis.edu
Wed Jun 21 21:29:09 PDT 2017

On 06/21/2017 05:29 PM, Christopher Samuel wrote:
> On 21/06/17 22:39, John Hearns wrote:
>> I would speculate about single socket AMD systems, with a smaller form
>> facotr motherboard, maybe with onboard Infiniband.  Put a lot of these
>> cards in a chassis and boot them disklessly and you get a good amoutn of
>> compute power.
> I thought it interesting that the only performance info in that article
> for Epyc were SpecINT and (the only mention for SpecFP was for Radeon).

I worried about this as well, assumed AMD was bragging about Integer performance
because their FP performance was worse.  The opterons were somewhat weak on this
front with a shared FP unit per two "cores".  Turns out AMD had a pleasant
surprise on that front with Epyc.

I found few interesting data points:

CPU         chips IntRate    FPRate  Compiler
======      =====    ====    ======  ==========
E5-2630  V4 x2        795       651  Intel compiler
E5-2699A V4 x2       1800      1090  Intel compiler v16
E5-2699A V4 x2       1160       760  Gcc -O2 v6.2
Epyc 7601   x2       2100      1660  Open64 v4.5.2.1
Epyc 7601   x2       1840      1340  Gcc -O2 v6.2
Epyx 7601   x1       1200       860  Open64 v4.5.2.1

Stream numbers are quite good as well, not surprising with double the channels.
While not a good indicator of overall performance, at least it's scaling the
bandwidth per core so it's not a bigger bottleneck than the previous generation.

Pretty impressive, AMD's fastest with gcc beats Intel's fastest with the Intel
compiler.  Open64 of course extends that lead.  Also interesting is that the
fastest Epyx single sockets do overlap with the most popular Intel dual sockets.

The Epyc + Open64 numbers on on specbench.org, the gcc -O2 numbers are from AMD
presented slides published on numerous tech sites after yesterday's announce.

>From what I can tell of pricing it looks like if you are trying to maximize
CPU2006 / node price it looks like the E5-2620 or E5-2630 on the Intel side and
the EPYC 7281 on the AMD side, at least for dual sockets.  It's hard to be
precise though because AMD hasn't posted performance numbers for their entire
line of Epyc chips yet.

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