ATI RADEON HD 4890 Crossfire
 

In the ATI Overdrive menu, we can see that we can select the GPU to configure from the drop-down menu, and, depending on the card, we can set the GPU clocks, the Memory clocks and we can also set the fan speed for each card, independently. In this menu we can also see the Current values of the GPU/Memory clocks, which usually show when no 3D application is on the 2D clocks, which are in this case 240/975. On the right side, there can be seen the temperature for each GPU, the activity percent and the fan speed percent.

http://www.pcshoptalk.com/forum/showthread.php?t=14878