Why is my GPU not being fully utilized?

Question

I happen to have two identical X201 Lenovo laptops, both with Windows 7 installed, latest drivers, etc. However, only one manages to run 3D computer games with decent performance.

I have gone through every configuration setting I can think of to find out why one is performing so much better than the other, without success. The only thing I can find (from Process Explorer) is that on the poor performance machine, the "GPU Usage" never seems to go above about 40%, whereas the other reaches above 90%. All other metrics are similar on both machines (CPU usage, RAM usage, dedicated/system GPU memory, etc).

So my question is: What might be limiting the GPU usage on one of the machines? I guessed it may be to do with power options to keep the machine cool, but all power options are similar on both machines. I have tried to force everything to "performance" on the low performance machine, with no change. I have also tried running GPU stress test tools but still the usage never goes above 40%.

Thanks for any ideas!

Answer 1

It turns out that it was related to heat, as magicandre1981 suggested. I imagine that the overheating machine has just been used more, and so perhaps the air filters are slightly more clogged or the fan isn't spinning quite so well.

It seems that the BIOS fan controller on the X201 is a bit too biassed towards being quiet rather than keeping the machine cool. For whatever reason, it was set such that the fan never goes to maximum speed, even at temperatures above 85 degrees C.

I solved the problem using http://sourceforge.net/projects/tp4xfancontrol/ and specifying the following in TPFanControl.ini:

Level=55 0
Level=60 1
Level=65 3
Level=70 7
Level=75 64

and selecting "Smart (TPFanControl.ini)" mode from the TPFanControl control panel.

Now the laptop runs 10 degrees cooler, with graphics processing finally returning to full capacity.