That's a quote from my post on ubuntuforums from some time ago:
I'm not completely sure but I think this is a problem for me too. I have a laptop HP 8540W with NVIDIA Quadro FX880M, core i7-720qm.
Output of nvidia-settings -q GPUPerfModes -t:
perf=0, nvclock=135, memclock=135, processorclock=270 ; perf=1, nvclock=405,
memclock=324, processorclock=810 ; perf=2, nvclock=550, memclock=790,
Switching between perf0 and perf1 is ok, compiz runs smooth, but as much as the nvidia-applet shows it never goes to perf2 mode.
I have done benchmarks with Unigine Heaven and Sanctuary getting 13 and 33 fps in Linux while with the same settings in Win7 I get respectively 24 and 52 fps (both with opengl rendering exact same settings) which was the first thing that made me think something is not working fine.
I have tried all the perflevelsrc hacks and with trial and error managed to lock it in perf0 and perf1 modes and other different combinations for ac and battery power but never to maximum performance although I ran glxgears for each setup and got around 5-6 different results ranging from 650 to 4000 fps.
I also tested WoW in wine with opengl rendering and it gets solid 30fps on max settings and 1600x900 resolution which is quite good but in Win7 I get around 40-45fps for the same settings (although this may be completely due to the game).
Most of all while running the Unigine Benchmarks my graphics card runs much hotter on Win7 than on Ubuntu which I'm quite sure means that I'm not running on max performance on Ubuntu.
Using Ubuntu 10.10 x64, 2.6.35-28-generic
nvidia drivers downloaded - tried with both development driver 260.19.26 and normal driver 270.41.06
In general, powermizer stops my gpu from going to it's normal frequencies for no apparent reason, or at least nvidia panel shows that.
I still have the same problems - everything reproduced also on Ubuntu 11.04 x64 2.6.38-8-generic, and partially reproduced on Fedora 15 ( I just ran a live cd and installed nvidia drivers for a couple of apps).
Problem persists with the latest drivers 275.09.07. Since my previous post I have also done benchmarks with specviewperf, nexuiz and a couple of opencl and cuda apps from the nvidia sdk and about 90% of them show that in Linux I get roughly 60% of the performance I get on Win7 Home Premium. Including really simple OpenCL apps which I don't think could be platform dependent in any way - example oclBandwidthTest from the SDK gives 8GB/s device to device bandwith in linux and 16GB/s in Windows, which is really straightforward since the memory clock is shown to work on 325MHz in linux where it's max frequency would be 790MHz.
Nothing unusual can be seen in my log files. Tell me if it would be of any help to post exact results of some benchmarks.
I would really appreciate any help, I usually prefer searching forums than posting when I have a problem but this really seems a dead end.