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Comment by dr_zoidberg | Hacker News Reader

> (maybe game physics?)

Not game physics, as it puts the CPU in a lower speed regime it'd have negative implications on the rest of the games performance. So far, that AVX512 requires this lower speed (due to thermals) is an implementation detail, and it could be expected that newer processes (Intels 10 or 7 nm?) would allow them to work AVX512 tasks on full speed.

Until that happens, and everyone has AVX512 (because it'd be a massive fail to have a game that requires you to have a HEDT Intel processor to play), it'd be a nice gimmick to have on very specific tech demos, and performance sensitive scientific code that you know will run on a certain machine with certain characteristics.

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Games will ship with AVX512 special paths once the AMD chips in consoles support it. Until then it is just a fancy feature to make already fast CPUs a bit faster.

Game programmers will put time into making slow CPUs faster. Outside tech demos or hardware marketing tie-ins no budget is allocated to making yet more spare capacity.

What kind of games care about such specific instructions? Unless you are writing something in assembly, that's not something game developers usually are focused on.

All kinds of games use AVX. Particularly, anything using Denuvo won't run without it.

AVX-512 isn't just wider execution units, it's different types of instructions, particularly some that fill in holes in the existing sets of instructions. Once it starts to be widely available, it will get used, and will eventually be a requirement, just like AVX has.

Ice Lake is introducing AVX-512 on Intel mobile, Tiger Lake will introduce it on desktop, presumably Zen3 will be introducing it on AMD.

Unity is a very high level engine, that uses C#, and it now has a system built in that lets you write code that looks like C# but will translate it to whatever SIMD instruction set is available, like ISPC.

There are also various libraries that leverage metaprogramming to do similar things. I don't think you understand what game devs are willing to do, to get a few more polygons and pixels on the screen!

> I don't think you understand what game devs are willing to do, to get a few more polygons and pixels on the screen!

Totally depends on the trade-offs. You can write your whole game in assembly, and target very specific hardware, and may be beat optimizing compiler (doubtful). But at what cost? Time spent on that could be spent on making more games.

Normal up to date hardware handles games just fine, as long as they are not using some abysmal and poorly parallelized engines. Modern CPUs with more cores are also helping that, especially after Ryzen processors opened the gates for it.

AFAIK all of the consoles use AMD chips so I wouldn't expect games to adopt AVX512 anytime soon.

And specifically the next generation of consoles is using Zen2 architecture, which does not support AVX-512.

That said, desktops can apply whatever optimizations they want. Denuvo uses AVX in their DRM, which is also not a thing on console, so presumably they will eventually incorporate AVX-512.

downclocking is per core, it should normally be very simple to get huge net speedups with AVX-512 despite the downclocking, in game physics or anything else.

its also relatively common to write multiple versions of SIMD code (or use tools like ISPC or metaprogramming) to leverage whatever SIMD instruction set a cpu has. Such as the DOTS system in Unity. Games will happily leverage AVX-512 as soon as a fair number of desktop cpus support it.

The downclock would only be on the core using the instruction.

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