Hi, First I would like to highlight that "X86_V2" is very specific to the implementation in numpy, basically this implies the support of all 128 bits SIMD extensions, i.e. SSE1,2,3&4, but does apparenty not requires any 256bit SIMD (AVX).
Ralph, the stats you are using are made on end-user hardware which gets replaced much faster than servers, while numpy is very likely to be used on elder hardware, especially for CI where elder hardware still ok and often recycled. For example, we are still renting severs which is X86_V2 but not X86_V3 for performing the CI/CD of our projects. Cheers, Jerome On Sat, 17 May 2025 20:55:00 +0200 Ralf Gommers via NumPy-Discussion <numpy-discussion@python.org> wrote: > On Sat, May 17, 2025 at 3:00 PM <m...@astro.utoronto.ca> wrote: > > > Hi Sayed, > > > > I'm a bit confused: does your suggested change mean that prre-2009 > > processors won't work at all, or that no use will be made of the (little) > > acceleration that they provided? The latter seems fine, but not working at > > all seems rather bad. > > > I don't think it's that bad. It's always a tradeoff between performance, > binary size, effort, and compatibility. We've had this discussion before, > e.g. when moving to SSE3 as the baseline, and decided that we should not > drop support for a feature if less than 99.5% of CPUs in the wild has > support, but if it's above we can do it. Previous bumps have not given any > significant pushback from our user base. > > >From https://github.com/numpy/numpy/issues/27851, half a year ago: > > *The most widely used data source for determining what hardware is out > there is, I believe, > https://store.steampowered.com/hwsurvey/?platform=combined > <https://store.steampowered.com/hwsurvey/?platform=combined>. That > currently says that SSE3 is at 100%, SSE4.1 at 99.78% and SSE4.2 at 99.70%. > Meaning that if we bump the baseline up to SSE4.2, we'd only be dropping > support for ~0.3% of systems with really old CPUs.* > > SSE 4.2 support as of today increased to 99.78%, so the number of CPUs we'd > drop support for moved from 0.3% to 0.22% in 6 months. That means we're > still being very conservative after this bump, IIRC more so than when we > dropped support for CPUs without SSE3. > > Cheers, > Ralf > > > > > Though I'd think that for any old processors one can just fall back to the > > standard `libm` implementations. > > > > All the best, > > > > Marten > > _______________________________________________ > > NumPy-Discussion mailing list -- numpy-discussion@python.org > > To unsubscribe send an email to numpy-discussion-le...@python.org > > https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ > > Member address: ralf.gomm...@gmail.com > > -- Jérôme Kieffer _______________________________________________ NumPy-Discussion mailing list -- numpy-discussion@python.org To unsubscribe send an email to numpy-discussion-le...@python.org https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ Member address: arch...@mail-archive.com
