SpeedFan is a freeware program that monitors fan speeds and temperatures in computers with a known monitoring chip. Its main feature is that it can control the speed of the fans according to the temperatures inside your pc, thus reducing noise and power consumption. Currently the only recognized (and useful) chips are WINBOND W83782D, which is found in ABIT BP6, and WINBOND W83627HF. If you've got any other motherboard with the same chip, this program is for you.