[mesa-users] alternative blas, lapack

[Amber Lauer]

So if I understand you guys correctly, you're saying it's probably not
worth it?

On Sun, Mar 8, 2015 at 11:09 PM, Francis Timmes <fxt44 at mac.com> wrote:

> silly me.
>
> upon reflection, drop-in lapack or blas “replacements” are doomed to have a
> small effect because many of the routines used in mesa/star are customized
> (e.g., the my_* modules in mesa/include/mtx_solve_routines.inc) for
> improved
> performance  with mesa (e.g., lower calling overhead, simd directives,
> etc).
>
> i’m posting this in case someone decided to follow up on the experiment ...
>
> fxt
>
>
>
>
> > On Mar 6, 2015, at 11:44 PM, Francis Timmes <fxt44 at mac.com> wrote:
> >
> > i gave this a try. editing $MESASDK_ROOT/bin/mesasdk_*_link to use
> > the os x accelerate framework was easy, fixing the build failures
> > caused by differences from the fixed test_output file in mtx/test,
> > num/test, net/test, and gyre/test was less fun.
> >
> > i ran a 30 msun 21 isotope net starting from the pre-main-sequence
> > for 2000 steps (midst core oxygen burning). no pgstar output, but
> > otherwise my stock setup for massive stars. on a 4 core laptop
> > a normal mesa build took 740 averaged over three runs.
> > using the accelerate framework took 712 s averaged over three runs.
> >
> > so in this specific case the speedup was ~3%.
> > of course, maybe i messed something up, your milage may vary, and
> > two dozen other caveats why this is not a definitive number.
> >
> > fxt
> >
> >
> >
> >> On Mar 6, 2015, at 8:07 AM, Richard Townsend <townsend at astro.wisc.edu>
> wrote:
> >>
> >> Good question — and to my knowledge, the answer is no. The blas and
> lapack libraries bundled with the SDK are the reference versions, and as
> such could be appreciably slower than tuned libraries (e.g., ATLAS). This
> is for obvious reasons: tuned libraries are architecture-specific, and
> given the hardware heterogeneity of x86_64 platforms there is  no
> meaningful default option.
> >>
> >> If you happen to have tuned libraries on your system, you can easily
> make the SDK use them by editing the $MESASDK_ROOT/bin/mesasdk_*_link
> scripts to emit the appropriate linker commands. I’ve used this in the past
> to link to the OS X Accelerate framework.
> >>
> >> cheers,
> >>
> >> Rich
> >>
> >>> On Mar 6, 2015, at 12:41 AM, Amber Lauer <alauer1 at tigers.lsu.edu>
> wrote:
> >>>
> >>> Is there some place where the relative merits of external vs SDK
> libraries for the math functions are discussed?
> >>>
> >>> --
> >>> Amber Lauer. M.S. Physics
> >>> PhD Student,
> >>> Dept. of Physics & Astronomy,
> >>> Louisiana State University
> >
>
>


-- 
Amber Lauer. M.S. Physics
PhD Student,
Dept. of Physics & Astronomy,
Louisiana State University
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