Comment # 8 on bug 73338 from Marian Domanik

I can confirm this too, using ATI Sapphire 7850 2GB OC, with fglrx drivers the
fan is absolutely silent after the OS boots up and automatically speeds up in
heavy load.

With these drivers, the fan speed is always constant, no matter what load.
Would be great if it would also change accordingly. Not sure how to help to fix
this, I can provide any information needed.