How do I detect a CPU bottleneck?

[Schytheron]

How do I detect a CPU bottleneck... I dont quite understand what to look at ... CPU usage ingame or GPU usage. And what is a good game for checking cpu bottlenecks??

Specs:
AMD Phenom II X4 955 BE @ 3.6 Ghz
Sapphire Radeon 7870 XT with Boost
Resolution: 1366x768

 

[Novuake]

Its not that simple, but yes, in some games you will have a CPU bottleneck, OC and that will relieve some of it.

 

[rex4235]

You could help dampen the effect by overclocking the 955. Its a BE so you should be anyway (unlocked multiplier) -- assuming you have an aftermarket cooler of course

 

[ihog]

When the CPU usage is at 100% and the GPU is lower than 100%, you technically have a CPU bottleneck.

 

[Novuake]

When the CPU usage is at 100% and the GPU is lower than 100%, you technically have a CPU bottleneck.

The thing is if the gaem of app cant use 4 cores, the CPU will not show at 100%.

 

[rex4235]

Unless you monitor all the cores individually i.e. CoreTemp

 

[Novuake]

Unless you monitor all the cores individually i.e. CoreTemp

Yes.

 

[Schytheron]

When the CPU usage is at 100% and the GPU is lower than 100%, you technically have a CPU bottleneck.

The thing is if the gaem of app cant use 4 cores, the CPU will not show at 100%.

I monitor all cores individually. But I cant seem to find a good game for CPU bottleneck detection.

I played Metro Last light and all cores were at like 60% while my gfx card was also at 60%... Thats normal right?

 

[ihog]

What settings are you using? Are you having any performance issues? If not, then you've got nothing to worry about.

 

[rex4235]

Some games (like Arma 3 beta) can lead you to believe you have a GPU bottleneck when you lower certain settings below a point. In A3, if you turn the smoke resolution down past medium it anticipates the user having a poor GPU and offloads the work to the CPU.

So my question would be, are you running low settings as a result of your poor fps?

 

[Schytheron]

Some games (like Arma 3 beta) can lead you to believe you have a GPU bottleneck when you lower certain settings below a point. In A3, if you turn the smoke resolution down past medium it anticipates the user having a poor GPU and offloads the work to the CPU.

So my question would be, are you running low settings as a result of your poor fps?

I ran Metro Last Light at High settings and when i pushed them to very high fps didnt change... soo im guessing my GPU isnt a issue at all. I also ran Crysis 3 and it seems i dont have a bottleneck. CPU usage was at 30-40% while GPU usage could go up to 100%. The wierd thing is that under 60 fps my gpu tries to push itself to get 60 fps, but as soon as i go over 60fps the gpu usage drops very much. Im suspecting that it isnt my CPU, maybe my GPU has some sort of power saving function... if that even exists...

 

[ihog]

That's odd. It does go over 60 FPS, though, correct?

 

[Schytheron]

That's odd. It does go over 60 FPS, though, correct?

Yes it does go over 60

 

[ihog]

Check your GPU temps while playing, and report back.

 

[Schytheron]

Check your GPU temps while playing, and report back.

I have now both overclocked my cpu and gpu... and right now i dont seem to notice any bottlenecks btw. GPU temps btw are very low. Getting 64c on load. My card can handle like 80-90c

I have also reinstalled windows and when I now ran Metro Last Light I could play on very high settings without any issues whatsoever. Must have had some problem with Windows. Maybe had malware or something

 

[likdaboo]

When the CPU usage is at 100% and the GPU is lower than 100%, you technically have a CPU bottleneck.

The thing is if the gaem of app cant use 4 cores, the CPU will not show at 100%.

i have an 8 core proccessor and a cpu bottleneck, if the percent is sticking between 50% - 60% then the cpu is bottlenecked.. if you have 8 cores, as its using 4 cores at 100%, then 10% on the other cores..

so id take your amount of cores and work out ther percentage it will use running 4 cores.. and see if its close
for example a 6 core proccessor bottlenecked would show around 66.6%

 

[Novuake]

i have an 8 core proccessor and a cpu bottleneck, if the percent is sticking between 50% - 60% then the cpu is bottlenecked.. if you have 8 cores, as its using 4 cores at 100%, then 10% on the other cores..

so id take your amount of cores and work out ther percentage it will use running 4 cores.. and see if its close
for example a 6 core proccessor bottlenecked would show around 66.6%

Not at all. CPU bottlenecks are not that simple. Bulldozer is a very good example of that.