Monitor voltages, fan speeds and temperatures using SpeedFan, a small powerful freeware utility for Windows.
It is a program which can help you monitor voltages, fan speeds and temperatures in computers with hardware monitor chips. SpeedFan accesses S.M.A.R.T. info and show hard disk temperatures. SCSI disks are supported too. If your motherboard's chip is fully supported, you can change the FSB, but this should be considered as a bonus feature.
SpeedFan can access digital temperature sensors and can change fan speeds, in order to reduce noise. It can find almost any hardware monitor chip connected to the 2-wire SMBus, System Management Bus (trademark belonging to SMIF, Inc.). SMBus is a subset of the I2C protocol.
SpeedFan works fine with Windows 9x, ME, NT, 2000, 2003, XP and Windows Vista. It works with Windows 64 bit too.