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FFmpeg devs boast of up to 94x performance boost after implementing handwritten AVX-512 assembly code
(www.tomshardware.com)
this post was submitted on 05 Nov 2024
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nice.
can usually get a pretty good performance increase with hand writing asm where appropriate.
don't know if its a coincidence, but i've never seen someone who's good at writing assembly say that its never useful.
To be fair, people who don't find assembly useful probably wouldn't get good at writing assembly
for sure, its perfectly reasonable to say "this tool isn't useful for me"
its another thing to say "this tool isn't useful for anyone"
Though you'd get the same speedup if you used SIMD intrinsics. This is just comparing non-SIMD to SIMD.
from the article it's not clear what the performance boost is relative to intrinsics (its extremely unlikely to be anything close to 94x lol), its not even clear from the article if the avx2 implementation they benchmarked against was instrinsics or handwritten either. in some cases avx2 seems to slightly outperform avx-512 in their implementation
there's also so many different ways to break a problem down that i'm not sure this is an ideal showcase, at least without more information.
to be fair to the presenters they may not be the ones making the specific flavour of hype that the article writers are.
yes, as i said
(they don't make that comparison in the article)
so its not clear exactly how handwritten asm compares to intrinsics in this specific comparison. we can't assume their handwritten AVX-512 asm and instrinics AVX-512 will perform identically here, it may be better, or worse.
also worth noting they're discussing benchmarking of a specific function, so overall performance on executing a given set of commands may be quite different depending what can and can't be unrolled and in which order for different dependencies.