Re: OpenBLAS and performance

[Ludovic Courtès]

Pjotr Prins <address@hidden> skribis:

> The last weeks I have been toying with OpenBlas and tweaking it boosts
> performance magnificently over the standard install we do now. A
> configuration for Haswell looks like:
>
>   
> https://gitlab.com/genenetwork/guix-bioinformatics/blob/master/gn/packages/gemma.scm#L64

Nice!

The ‘openblas’ definition has this comment:

          ;; Build the library for all supported CPUs.  This allows
          ;; switching CPU targets at runtime with the environment variable
          ;; OPENBLAS_CORETYPE=<type>, where "type" is a supported CPU type.

Do you achieve similar performance by setting OPENBLAS_CORETYPE=haswell?
It would be nice if OpenBLAS would do this automatically.

> Or are channels going to solve this for us?

No, I don’t think channels have much to do with this kind of issue.

But see the discussion we had on this topic:

  https://lists.gnu.org/archive/html/guix-devel/2017-08/msg00155.html
  https://lists.gnu.org/archive/html/guix-devel/2017-09/msg00002.html

> Btw the latest stable release worked fine too:
>
>   
> https://gitlab.com/genenetwork/guix-bioinformatics/commit/474524a5a0d57744c1727442b33d8f2889eb0397

It was updated in ‘core-updates’, so it’ll hopefully land soon!

Ludo’.