A small application that shows you fan speedSpeedFan is a simple utility that displays the fan speed, voltage and chip temperature of your PC.
With SpeedFan you can access digital temperature sensors and modify fan speeds and even change the FSB on some hardware. SpeedFan is capable of accessing S.M.A.R.T. info and display hard disk temperatures.
The program can detect almost any hardware chip connected to the 2-wire SMBus and is compatible with Windows 9x, ME, NT, 2000, 2003, XP and Vista (both 32 and 64-bit versions). SpeedFan can handle almost any number of South Bridges, hardware monitor chips, temperature readings, voltage readings, fan speed readings and PWMs.