GPU overclock effect

[SCG_motoadve]

Why does overclocking GPU increases fps if the bottleneck is the CPU?

When I OC my card I go from steady hi 70s low 80s fps to hi 80s and 90.

[dburne]

It is also about balance. You have a very nice CPU and GPU, they are able to get along better so to speak.

Your CPU is able to feed that nice GPU better than say my older i7 4820k feeds my 2080 Ti.

[macnkill]

I know this is going to sound like a smart ass answer, but, because the CPU isn’t the bottleneck.

 

The more in-depth answer is that there is a complicated relationship between how a game utilizes ram, CPU cores, and the GPU cores and GPU ram. If the game is highly multithreaded, then it will utilize more cores and you start getting bottlenecks elsewhere such as ram and That’s just one example, there are other factors too. If you choose to run a game at 2160p rather than 1080p, the load on the gpu is greatly increased, without much of an increase of load on the cpu or other components. The oculus is one of those devices that puts additional load on the gpu without a proportionate increase of load on the cpu. It not only had a slightly higher resolution than a typical 1080p display, it requires rendering from two different viewpoints. 

[chiliwili69]

Previous to version 3.007 we saw that when you have an 1070 or above the bottleneck was always the CPU. (For SteamVR SS around 150%).

We don´t have enough data for 3.007 to conclude that CPU is still the main bottleneck. Perhaps this new release (with the modified tree rendering technique) is loading more the GPU and the CPU is starting to not be the true bottleneck.

To have some data you could run the test with/without doing OC in your GPU.

 

Anyhow, overclocking your GPU will always help your overall results even if the CPU is still the bottleneck. Let me explain this.

If your CPU is producing framerates (to be rendered) at let say 3ms, then your GPU has plenty of time (8ms, since 11ms-3ms) to do the render and overclock will not play a difference.

But if your CPU is really constraining your system, it will produce framerates at 9ms, then you GPU need to do the render in only 2ms in order to be below 11ms (ie 90fps). So overclocking here the GPU for sure will help to achieve this better. But the clear guilty guy is the CPU.