CPU Affinity and FPS in games.

[SImoHayha]

So what does CPU Affinity do exactly? I was messing around with some things playing BF4 and when I sent the affinity to cores 0-4 it completely and utterly tanks. It goes to 72 FPS then 10 then 15 then 68 then so on and so on. However when all of the cores for affinity are on it plays perfectly fine. So what is the big idea ?  And waht does CPU Affinity help with?

[AnonymousGuy]

Very old software used to have issues where it couldn't handle multi-core CPUs and you could set affinity to force it into only "seeing" 1 core.

 

Nowadays you should never need to touch affinity.

[othertomperson]

Setting affinity is good if you have an old game that will crash if you OS tries to spread its single-core usage over multiple CPU cores. This was a serious problem back when dual cores were new and Windows Vista tried to do this a lot.

 

I haven't had the need to manually set CPU affinity for a long time though, even with really old games so it seems like the OS has stopped causing problems here.

 

BF4 is a game that can use up to 8 cores effectively. It stands to reason that it would lose performance if you tell it not to use a decent amount of your CPU.

[Silyy097]

So what does CPU Affinity do exactly? I was messing around with some things playing BF4 and when I sent the affinity to cores 0-4 it completely and utterly tanks. It goes to 72 FPS then 10 then 15 then 68 then so on and so on. However when all of the cores for affinity are on it plays perfectly fine. So what is the big idea ?  And waht does CPU Affinity help with?

CPU Affinity helps when you want a certain number of cores tasked to this certain workload and the rest of the cores tasked to this other workload (Eg on a 6300, 4 cores to editing and the other 2 to idle, used for everything else) so that the computer will not lag like crap on older computers.

 

When you are gaming, dont set the affinity, just leave it to utilize all cores.