Re:Knight’s Landing: Atom with AVX-512
by rbanffy on Saturday December 10, 2022 @08:05PM
(#33938856)
> "AVX-512 is a huge fraction of modern cores", and "give us more cores instead". Let's instead use the hardware we have
If what you do can use a wide SIMD pipeline, then, by all means, get AVX-512.
If what you want is to have lots of branchy processes running serving different things, then more cores is a better idea.
I'd suggest the best of both worlds - asymmetric cores. Put a couple that have wide SIMD pipelines, alongside a couple others that don't, but may be smaller and more numerous.
AVX-512 tasks that are scheduled to non-AVX-512 trap and are scheduled to AVX-512 cores. Tasks that don't trap continue running wherever the kernel thinks is best.
If what you do can use a wide SIMD pipeline, then, by all means, get AVX-512.
If what you want is to have lots of branchy processes running serving different things, then more cores is a better idea.
I'd suggest the best of both worlds - asymmetric cores. Put a couple that have wide SIMD pipelines, alongside a couple others that don't, but may be smaller and more numerous.
AVX-512 tasks that are scheduled to non-AVX-512 trap and are scheduled to AVX-512 cores. Tasks that don't trap continue running wherever the kernel thinks is best.