I know that if you go into the BIOS, you can set the fan speed of your heatsink.
There is a program called SpeedFan which access your motherboards settings and shows you the temperature of your cpu and you could also use it to regulate the speed of your fans if you have them plugged into your motherboard.
Here is an example of what the software looks like:
okay, for some reason, only the cpu0 fan is showing that its going, and its going at about 4000 rpm, and is very loud. the others aren't showing at all, but the fans all seem to be going round.