From: Dave Love <fx@gnu.org>
To: guix-devel@gnu.org
Subject: Re: OpenBLAS and performance
Date: Fri, 22 Dec 2017 14:35:22 +0000 [thread overview]
Message-ID: <87h8si25lh.fsf@albion.it.manchester.ac.uk> (raw)
In-Reply-To: 20171220192802.GA8426@thebird.nl
For what it's worth, I get 37000 Mflops from the dgemm.goto benchmark
using the current Guix openblas and OPENBLAS_NUM_THREADS=1 at a size of
7000 on a laptop with "i5-6200U CPU @ 2.30GHz" (avx2). That looks about
right, and it should more-or-less plateau at that size. For comparison,
I get 44000 on a cluster node "E5-2690 v3 @ 2.60GHz" with its serial
build of 0.2.19. (I mis-remembered the sandybridge figures, which
should be low 20s, not high 20s.)
If you see something much different, perhaps the performance counters
give a clue, e.g. with Guix' scorep/cube, oprofile, or perf.
I've sent a patch for the correct cache size on haswell, but I don't
think it makes much difference in this case.
next prev parent reply other threads:[~2017-12-22 14:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-19 10:49 OpenBLAS and performance Pjotr Prins
2017-12-19 17:12 ` Ludovic Courtès
2017-12-20 11:50 ` Dave Love
2017-12-20 14:48 ` Dave Love
2017-12-20 15:06 ` Ricardo Wurmus
2017-12-22 12:24 ` Dave Love
2017-12-20 17:22 ` Pjotr Prins
2017-12-20 18:15 ` Ricardo Wurmus
2017-12-20 19:28 ` Pjotr Prins
2017-12-20 20:00 ` Ricardo Wurmus
2017-12-20 20:32 ` Pjotr Prins
2017-12-20 19:02 ` Eric Bavier
2017-12-21 16:38 ` Dave Love
2017-12-20 23:02 ` Ricardo Wurmus
2017-12-21 10:36 ` Pjotr Prins
2017-12-21 14:43 ` Ludovic Courtès
2017-12-22 14:35 ` Dave Love [this message]
2017-12-21 16:17 ` Dave Love
2017-12-21 16:46 ` Ricardo Wurmus
2017-12-21 14:55 ` Ludovic Courtès
2017-12-22 12:45 ` Dave Love
2017-12-22 15:10 ` Ludovic Courtès
2017-12-22 16:08 ` Pjotr Prins
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