[mesa-users] alternative blas, lapack

[Richard Townsend]

Thanks for the info, Frank. This is a why I generally shy away from using optimized libraries -- the performance gain is typically not worth the effort.

Cheers,

Rich



> On Mar 7, 2015, at 12:44 AM, 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