GPU-Z ~ a free utility designed to give you all information about your video card and GPU. It provides displays adapter, GPU and display information. It also provides displays overclock, default clocks and 3D clocks. I use it to trace my ATI HD 4870 GPU temp and fan speed. It has log to file function. Therefore, you can trace these during game play.
Download SpeedFan ~ a freeware program that monitors voltages, fan speeds and temperatures in computer
SpeedFan is a freeware program that monitors voltages, fan speeds and temperatures in your computer. It is a great tool for overclocker like me. You can monitor your CPU cores temperature and CPU fan speed too. Its main features are monitor fan speed. However, it does not end here. It has other useful features like access S.M.A.R.T. info on hard disk, change the FSB on some hardware and control fan speed. It can be used on Windows 9x, ME, NT, 2000, 2003, XP and Windows Vista. It works with Windows 64 bit too.