Clear up obvious confusion about CPU overhead at different resolutions.

[pyrojoe34]

So there are a lot of people posting and talking about the role and importance of the CPU vs GPU at different resolutions.

 

The general statement I see is something along the lines of: "4k gaming is more GPU bound and 1080p gaming is more CPU bound" or "1080p gaming takes more CPU power than 4k gaming."

 

I'll start this off by saying that this is not a false statement, but it is a very misleading statement. 1080p is not, by any means, inherently more demanding on the CPU than 4k. The biggest factor to increasing the burden on the CPU is NOT the resolution, it is the framerate. There are some parts of a game's processing needs that are computed by the CPU (often things like physics) and the amount of processing the CPU needs to do for SOME CPU bound processes are directly related to the amount of frames per second are being rendered.

 

So, a running a game at 1080p/60fps will NOT take more CPU power than running a game at 4k/60fps. It is actually more likely that 4k/60fps would take slightly more CPU power than 1080p/60fps (depending on the game and engine design). The reason the statements above have become popular is because given the same system (and without using frame lock or v-sync), games at 1080p might run at 130fps while games at 4k might only run at 60fps due to the bottleneck presented by the GPU. Since running the game at 4k only has to calculate framerate-dependent CPU processes less than half as often as the 1080p case, the CPU burden will be less and you will see that as the CPU being used more at 1080p than at 4k.

 

I'm sure many of you realized this but I can't help but get the impression that many people saying this in threads did not understand the reason behind what they are saying. I just thought I would share my understanding of the subject for those who may not be aware of what the reason behind this effect is.

[RGProductions]

Thank you.

[Guest]

5 minutes ago, pyrojoe34 said:

many people saying this in threads

Sources please!

[pyrojoe34]

7 minutes ago, Dutch-stoner said:

Sources please!

I'm not going to call out specific people and put them on the spot and even if I did what they said is not wrong, just potentially misleading.

 

You can find plenty of examples of this if you look around though, especially in Ryzen threads (saying Ryzen is fine for 4k but bad for 1080p is the exact same logic) and people asking about CPU bottlenecks and stuff.