CPU Affinity for games

[flow]

Hello Blur Busters,

I have a question for you - is it good to change the CPU affinity for games?
I am currently running CS2 without CPU0 and my buddy runs Rust on every second CPU Thread (0, 2, 4, ...)
He said he got a massive FPS boost from it so I started to dig a bit.
I have a R7 7800X3D and he has a R7 9800X3D, both 8 cores 16 Threads.
My theory was always, to leave CPU0 so Windows can use this thread for backround stuff.

After reading some stuff about CPUs I am still not sure how things actually work.
I was reading something about that every core switches between Threads to always be working so that would make sense then to limit the game to every second Thread(?) If the game keeps only a number of Threads bussy it basically uses more cores and makes more space for backround stuff(?)

Maybe some of you can give me some tips if this is actually benefintial in therms of FPS or performance in general.

[Dalek]

Personally I've never bothered with it, ever. I think CPU Affinity is more for software development debugging and troubleshooting purposes.

[flow]

I will do some (ingame) benchmarks later today - it would be interesting to see if any values change

[flow]

Small update:
After some tests it seems to have little effect only.
My CPU: Ryzen 7 7800X3D
I tested with ingame benchmarks in CS2 on Ancient and Dust 2 (6 Tests per testcase)
From my testing the "best" results were without CPU0.
I tested: Every CPU; without CPU0; without CPU0 and CPU1; Without CPU1, CPU3, CPU5,...

Again little effect on AVG1% lows, bit more AVG FPS but nothing mayor IMO.
I think I had like around 290 1%lows normal and 300 without CPU0 (avg of 6 tests)
But I also saw that 6 tests prob are not enough since I saw that between tests values were changing +-25 or more at times

If any of you want to try out something for CS2 I recommend without CPU0 but test yourself and seeif you get any improvement

(Can post the results if any of you want to see the raw numbers)

tl;dr:
Changin CPU affinity probably is not worth it, you can try without CPU0 for CS2 on a Ryzen7 7800X3D but do your own testing

[Sz3ypy]

In my case its better with core0 ( 12700k) cs2 only on p-cores , but I make affinity for gpu , USB and nic