Re: Bumping CPU baseline to x86-64-v2
Ralf Gommers via NumPy-Discussion <[email protected]>
| Newsgroups | gmane.comp.python.numeric.general |
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| Message-ID | <CABL7CQhGJG5fFdmQ7a2UHaJJW5wtcWr+A07F-b=Pxy9X56bHQw@mail.gmail.com> |
On Sat, May 17, 2025 at 3:00 PM <[email protected]> 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 -- [email protected] > To unsubscribe send an email to [email protected] > https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ > Member address: [email protected] > _______________________________________________ NumPy-Discussion mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ Member address: [email protected]