Hi, have been controlling my 8800GT's fan using fan profiles with Rivatuner, i.e. if temp goes above 50c then fan speed 40%, if above 60c then fan speed 50% etc., etc. These work fine, but can take a bit of setting up. After re-installing XP, had a bit of a google and came across a much better way of controlling the fan, and a lot easier to setup. Go to the poweruser tab, then Rivatuner\fan, enter 3 in the AutoFanSpeedControl setting,
go to customise\low level system settings,
check the "Enable low-level fan control" box and enter the following values:
Duty Cycle Min: 36 (this is the fan speed % the card will start off with. I've used 36% as it's silent to my ears. Change to whatever you like)
Duty cycle Max: 100
T Min: 52
T Range: 32
T Operating: 77
T Low Limit: 0
T High Limit: 80
Check the Apply fan settings at windows startup" box and you're ready to go!
Using these settings, the fan speed will linearly increase or decrease in accordance with the gpu's temp. I've not gone above 74C even after a heavy COD4 session with the room heating full on!
What do the other settings mean? Google because I don't know lol!
Warning! Use incorrect settings and you may bork your card! Use at your own risk!!

go to customise\low level system settings,

check the "Enable low-level fan control" box and enter the following values:
Duty Cycle Min: 36 (this is the fan speed % the card will start off with. I've used 36% as it's silent to my ears. Change to whatever you like)
Duty cycle Max: 100
T Min: 52
T Range: 32
T Operating: 77
T Low Limit: 0
T High Limit: 80
Check the Apply fan settings at windows startup" box and you're ready to go!
Using these settings, the fan speed will linearly increase or decrease in accordance with the gpu's temp. I've not gone above 74C even after a heavy COD4 session with the room heating full on!

What do the other settings mean? Google because I don't know lol!
Warning! Use incorrect settings and you may bork your card! Use at your own risk!!