On Nov 5, 3:01 pm, "William Stein" <[EMAIL PROTECTED]> wrote:
> On 11/5/07, Martin Albrecht <[EMAIL PROTECTED]> wrote:
>
> > Hi,
>
> > this is probably due to the faster BLAS implementation on my notebook (and
> > the
> > standard GSL on your's). So we could remember which BLAS we use and default
> > to LinBox if we have a fast BLAS (OSX, ATLAS, Goto).
>
> The current plan with Sage is to switch to including ATLAS standard
> with Sage. Then the Sage will always have a fast BLAS.
>
> A year ago that would be crazy talk, but building ATLAS has very
> *massively* improved during the last year, so this is now quite
> reasonable.
And ATLAS also offers multi threaded BLAS Level 3 operations which
could be used by ffpack for matrix-matrix multiplies depending on the
algorithm used. The optional ATLAS.spkg is single threaded, but I am
working on add optional support to build ATLAS multi threaded. Problem
is that it takes roughly "number of cores" times to build since it
tunes itself for 1 to "number of cores" each. I am trying on sage.math
later on today to see if there is any benefit/how large matrices have
to become before we see an improvement.
I did some benchmarking with LinBox's rationalSolver and multi
threaded BLAS (ATLAS, Goto as well as Intel) did run slower than
single threaded, mostly due to the fact that the rational solver uses
BLAS Level 2 mostly, which is usually slower when multi threaded (due
to the higher overhead of setup of operations)
Cheers,
Michael
>
> -- william
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/
-~----------~----~----~----~------~----~------~--~---
