i had this problem of huge fan noise when i'm using fglrx driver for my x1950pro card. I recently found this:
http://www.phoronix.com/forums/showthread.php?t=6522
It's basically a modified radeontool that tweaks some registers in the card to turn off unused rendering pipes.
I tried it myself and it works fine - card quietted down after 15 secs after turning it on, so i'm putting the link here for people in need.
steps
become root:
su -
then:
Code:
wget http://nskunca.pbf.hr/~vedran/ati/radontool.tar.gz
gunzip *tool.tar.gz
tar xvf *tool.tar
cd rad*
cp radeontool /bin/radeontool_power_low
radeontool_power_low power low
It seems to work fine with newer generation of cards, like x1600+; there have been reported hard lockups when using it on a x1400 radeon. No reports for the effect on the 2000+ series yet.
i atattched the modified radeon tool in case the original web site is down for some reason
if you get some error like: "Radeon control memory not found" try the attatched version