Osiris: {QUESTION} AVX 512 Optimizations

Created on 15 Dec 2019 · 6Comments · Source: danielkrupinski/Osiris

Is the AVX 512 instruction set properly compatible with the Osiris Source? Or do we have to stick with AVX/AVX2 for optimization of the cheat?

Source

VuBrian22

Most helpful comment

AVX-512 instructions are powerful. With great power comes great responsibility. It seems unwarranted to disable AVX-512 by default at this time. Instead, the usual engineering evaluations should proceed. Check your Mainboard Vendor and BIOS Settings.

0xE232FE on 17 Dec 2019

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All 6 comments

is AVX 512 significant different from AVX 2 ? My CPU only support AVX 2 :(

tirziz on 15 Dec 2019

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@tirziz I mean I have a supported CPU. I'm just curious. I do know that if the code is not very AVX512-friendly (many non-vectorized pieces of code in between of vector code), then due to SKX "frequency throttling", AVX512VL could be sometimes more beneficial. In which it uses EVEX prefix encoding; something very different from what AVX2 uses. And basically if the encoding methods aren't supported and compatible to the code then it starts to breaks everything instead of optimizing them.

VuBrian22 on 15 Dec 2019

UPDATE: I just tried compiling the source through AVX 512 and it crashes on inject. So I guess I answered my own question. I'll keep this open for discussion until I can find a fix submit a pull request or until I give up.

VuBrian22 on 16 Dec 2019

0xE232FE on 17 Dec 2019

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@0xE232FE Thank you for your input. I have decided to just stick with AVX 2 until compatibility has been confirmed. My CPU is capable of running AVX-512 instructions however the code isn't AVX 512 friendly so it crashes on injection. This issue is closed.

VuBrian22 on 18 Dec 2019

If your CPU is Intel Core i7, i9, Xeon or Phi, you can try compiling with AVX512 and for sure it'll be much better optimized. If it won't load or crash then switch back to AVX2.