Originally Posted by Lithorus
Try adding this to /etc/modprobe.d/options
It really helps (in my case I have sometimes the Xid and black screen or the horizontal screen shaking) - great!
But it seems as if this option causes the GPU not to change the frequency anymore. nvclock -s returns constant values. Without the option the GPU frequency goes down when there is no GPU activity. (Which is okay because I had the horizontal screen shaking exactly when the frequency changes).
Can someone confirm that NVreg_RegistryDwords="PerfLevelSrc=0x2222" disables GPU frequency scaling?