all messages for Guix-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
From: "Ludovic Courtès" <ludovic.courtes@inria.fr>
To: zimoun <zimon.toutoune@gmail.com>
Cc: guix-devel <guix-devel@gnu.org>
Subject: Re: Guix-HPC activity report
Date: Fri, 15 Feb 2019 18:09:35 +0100	[thread overview]
Message-ID: <87d0ntm10w.fsf@inria.fr> (raw)
In-Reply-To: <CAJ3okZ1fSoLeEOWPuJomS6TjE1AUDOw6Ch62Vby9D5XvXWwfLg@mail.gmail.com> (zimoun's message of "Thu, 14 Feb 2019 16:35:37 +0100")

Hi Simon,

zimoun <zimon.toutoune@gmail.com> skribis:

> In the Guix FFTW package definition, there is a comment about AVX.
>
> Well, is it still accurate ?
> Is Guix binary still slower than other ?

The comment links to
<http://fftw.org/fftw3_doc/Installation-on-Unix.html>, which reads:

  Enable various SIMD instruction sets. […] FFTW will try to detect at
  runtime whether the CPU supports these extensions.  That is, you can
  compile with --enable-avx and the code will still run on a CPU without
  AVX support.

So I believe the numbers one gets with the ‘fftw’ package in Guix are
the best one can get because FFTW does the right thing of using the
right version of its hot functions at run time.  (That said, you can
redo the benchs, and if this is not the case, it’s a bug! :-))

See also this article, which addresses this topic:

  https://guix-hpc.bordeaux.inria.fr/blog/2018/01/pre-built-binaries-vs-performance/

Thanks,
Ludo’.

  reply	other threads:[~2019-02-15 17:09 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-12 13:51 Guix-HPC activity report Ludovic Courtès
2019-02-12 14:11 ` Laura Lazzati
2019-02-12 15:36   ` zimoun
2019-02-12 16:54     ` Ricardo Wurmus
2019-02-13 17:39 ` Pjotr Prins
2019-02-15 17:23   ` Ludovic Courtès
2019-02-14 10:25 ` Marco van Hulten
2019-02-14 14:43   ` Ludovic Courtès
2019-02-14 15:35     ` zimoun
2019-02-15 17:09       ` Ludovic Courtès [this message]
2019-02-22 15:41         ` zimoun

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87d0ntm10w.fsf@inria.fr \
    --to=ludovic.courtes@inria.fr \
    --cc=guix-devel@gnu.org \
    --cc=zimon.toutoune@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/guix.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.