Affected CPUs: AVX-512 capable CPUs. Intel Xeon, Zen 4 AMD Ryzen and EPYC and up.
Affected function: UYVY to YUV422 format conversion (pixel-level color encoding).
Speedup: 18/10.98 = 1.64x (Since all AVX512 cpus should support and previously have used avx2(56)).

Apparently as part of an ongoing series of rewrites, they made a color encoding conversion function run 64% faster on server CPUs and somewhat recent AMD CPUs

[–] sxan@midwest.social 3 points 3 days ago (1 children)

Christ. I am so behind on CPU terminology.

I get tripped up by the families, and the modifiers, and AMD doesn't help with their naming. Ryzen 5 5600. R 7 5800. R 7 5800H. R 7 5800X. Ryzen 7 7800X3D. Ryzen 7 9800. I know these also fall into different families, which have different capabilities, but then there are things like AVX-512.

Does something like avx512 show up in the flags of /proc/cpuinfo? I've looked at cpu-x; it dumps info like AVX(1, 2) - how does that relate to AVX-512? The Family is also number and not the names AMD uses, like "Summit Ridge" or "Raven Ridge". Is there a tool to translate this information?

[–] Redjard@lemmy.dbzer0.com 5 points 3 days ago (1 children)

yes, zen4 is the ryzen 7xxx ans onwards. I think they will change the naming scheme again after the 9xxxs now though.

In my case my 5xxx cpu shows avx2 (256bit) in /proc/cpuinfo, I assume you will find avx512 there if you have it.

Also apparently there are mobile and server cpus with 7xxx names that are zen3. It is a mess certainly.

[–] Scarlet0952@lemm.ee 2 points 2 days ago

Yes, avx512 shows up in cpuinfo, although with the spec consisting of many optional modules and not being a monolithic thing, each supported part will show up separately.

My 7800X3D has these avx512 flags: avx512f avx512dq avx512ifma avx512cd avx512bw avx512vl avx512_bf16 avx512vbmi avx512_vbmi2 avx512_vnni avx512_bitalg avx512_vpopcntdq

[–] swab148@lemm.ee 2 points 3 days ago

Good news for my server!

[–] jupdown@lemmy.ca 1 points 2 days ago (1 children)

I'd be interested to see the performance jump on a Zen 5 (or Xeon) CPU given that Zen 4 does that "double pump" approach to AVX512.

[–] Kissaki@programming.dev 1 points 1 day ago

I wanted to read about double pump but the linked article looks like a general benchmark, without an explanation of that concept?