2 ms·
> Another proof that Linus is not always right. No, this is just a case of the right answer changing over time, as good AVX-512 implementations became availabl
by wtallis 3y ago
> Another proof that Linus is not always right.
No, this is just a case of the right answer changing over time, as good AVX-512 implementations became available, long after its introduction. And nothing in this article even comes close to addressing the main concern with the early AVX-512 implementation: the significant performance penalty it imposes on other code due to Skylake's slow power state transitions. Microbenchmarks like this made AVX-512 look good even on Skylake, because they ignore the broader effects.
- nwallin 3y agoTo add to your point, this benchmark would not have run on Skylake at all. It uses the _mm512_maskz_compress_epi8 instruction, which wasn't introduced until Ice Lake.
- SomeoneFromCA 3y agoSo your point he is indeed always right? Or was right in that particular case (he was not)? If you remember, Linux complained not about the particular implementation of AVX-512, but the concept itself. It is also kinda looks ignorant of him (and anyone else who thinks the same way) to believe that AVX-512 is only about 512 or it has no potential, being a just simply better SIMD ISA compared to AVX1/2. What he did he just expressed himself in his trademark silly edgy maximalist way. It is an absolute pleasure to work with, gives great performance boost, and he should have more careful with his statements.
- a1369209993 3y ago> So your point he is indeed always right? No, their point is that this does not refute said hypothetical claim. That is, their point is that it is not, as you claimed: > Another proof that Linus is not always right. (I don't know if their point is correct, but it's of the form "your argument against X is invalid", not "X is correct".)