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Re: IBM POWER9 SIMD support? (Was: SIMDebian: ...)




Hi Kingsley,

On Sat, Feb 16, 2019 at 11:43:46AM -0800, Kingsley G. Morse Jr. wrote:
> My understanding is IBMs "POWER9" CPUs 
> 
>     1.) have SIMD instructions[1] and
> 
>     2.) are used by the new, and very cool, open
>         *hardware* Talos II workstations[2], which
> 
>     3.) already run Debian.

Debian's ISA baseline for ppc64el is Power8, so a Power9 branch of
SIMDebian makes sense.

Actually I already have (root) access to a Power9 VM, applied from IBM.
And I agree that Power architecture is a wonderful candidate
architecture for high performance computing, since one of my old tests
suggested that Power8+OpenBLAS is basically as fast as E5-2687Wv4+MKL
for 4096x4096 double precision matrix production[2]. The Power SIMD
instruction set (VSX, or say altivec) was available since Power8 (IIRC),
and many scientific software are already optimized with VSX.

However Power machines are really too expensive so I don't expect a
SIMDebian (Power9) community in reasonable size. So my main focus is on
x86_64 architecture, which has the largest potential user community.
That said, you are welcome to join the group[1] and help maintain the
power9 branch :-)

[1] https://github.com/SIMDebian/ 
[2] I think Power8/9 architecture benefits a lot from its enormous cache
    size at this point.