Just to let people know, that since on 9.04, there is no more "options" file in modprobe.d, just create nvidia.conf and add line in there...
sudo nano /etc/modeprobe.d/nvidia.conf
add line options nvidia NVreg_RegistryDwords="PerfLevelSrc=0x2222"
And of course, for those not willing to lock in 3D performance, there is always an option to control clocking manually through nvidia, by adding Option "Coolbits" "1" to xorg.conf
Just to let people know, that since on 9.04, there is no more "options" file in modprobe.d, just create nvidia.conf and add line in there... d/nvidia. conf
sudo nano /etc/modeprobe.
add line options nvidia NVreg_RegistryD words=" PerfLevelSrc= 0x2222"
And of course, for those not willing to lock in 3D performance, there is always an option to control clocking manually through nvidia, by adding Option "Coolbits" "1" to xorg.conf