Re: OpenBLAS and performance

[Ricardo Wurmus]

Pjotr Prins <address@hidden> writes:

>> > If I compile for a target it
>> > makes a large difference.
>> 
>> The FAQ document[1] says this:
>> 
>>   The environment variable which control the kernel selection is
>>   OPENBLAS_CORETYPE (see driver/others/dynamic.c) e.g. export
>>   OPENBLAS_CORETYPE=Haswell. And the function char*
>>   openblas_get_corename() returns the used target.
>> 
>> [1]: https://github.com/xianyi/OpenBLAS/wiki/Faq
>> 
>> Have you tried this and compared the performance?
>
> About 10x difference on 24+ cores for matrix multiplication (my
> version vs what comes with Guix).
>
> I do think we need to default to a conservative openblas for general
> use. Question is how we make it fly on dedicated hardware.

Have you tried preloading the special library with LD_PRELOAD?

-- 
Ricardo

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