Speedfan

speedfan
speedfan
Speedfan

If you need a tool that can change your computer’s fan speeds, read the temperatures of your motherboard and your hard disk, read voltages and fan speeds and check the status of your hard disk using S.M.A.R.T. or SCSI attributes, then try Speedfan.

It’s not just for fans. In fact on my Acer laptop it didn’t actually detect the fan at all. But did give loads of other information