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AVX512 is garbage. It incurs a massive performance hit from both frequency and mode-switching penalties. Apart from a few niche HPC and ML applications which
by nate_meurer 6y ago
AVX512 is garbage. It incurs a massive performance hit from both frequency and mode-switching penalties. Apart from a few niche HPC and ML applications which you'll never encounter, AVX512's most compelling use cases are to drive Intel's shady market fragmentation, and to create more bullshit FP benchmarks that Intel can claim to win.
https://www.extremetech.com/computing/312673-linus-torvalds-i-hope-avx512-dies-a-painful-death https://www.extremetech.com/computing/312673-linus-torvalds-...
- pixelpoet 6y agoNow that we've covered both ends of hyperbole, it's maybe worth noting that a lot of CPU parallel tasks can be well accelerated by ISPC, which can make reasonably effective use of AVX512 (with the aforementioned clock speed caveat): https://www.mail-archive.com/ispc-users@googlegroups.com/msg00202.html https://www.mail-archive.com/ispc-users@googlegroups.com/msg... Also, AVX512 is a much nicer (orthogonal) ISA than SSE or AVX2. While there are some niche applications that need larger amounts of memory than GPUs can offer, it's worth noting that this speedup comes from making the CPU act more like a GPU, and they aren't as fast as GPUs acting like GPUs (which are essentially many 32-wide vector units, rather than AVX512's 16-wide).
- floatboth 6y agoNah, to be fair, the most compelling application is: https://gamozolabs.github.io/fuzzing/2018/10/14/vectorized_emulation.html https://gamozolabs.github.io/fuzzing/2018/10/14/vectorized_e...
- shaklee3 6y agoThis is not true anymore: https://travisdowns.github.io/blog/2020/08/19/icl-avx512-freq.html#summary https://travisdowns.github.io/blog/2020/08/19/icl-avx512-fre...
- mcdevilkiller 6y agoThat's an i5. When Cloudflare talked about the issue, they were using high performance Xeons.
- shaklee3 6y agoI'm aware, but the ice lake xeons are starting to ship.