At stock settings, MSI's 6600 GT runs at 500/1000 MHz. Those stalwart overclockers looking for more should use the Coolbits registry hack to unlock the frequency selection dialog in the NVIDIA drivers. Like other manufacturers, MSI's warranty will not cover any damage to the hardware resulting from overclocking-related overheating. In our test, the driver's automatic detection routine determined the maximum safe overclock for our card to be 571/1142 MHz.

The Core Cell 3D Center offers another window to permanently save the increased frequencies. The frequencies and voltages for both the GPU and the memory can be adjusted in very fine steps in the VX-Tune interface.

At default speeds, the GPU temperature ranged from 48 to 59 degrees Celsius (2D/3D mode). Overclocking the card increases the temperature to 49 to 68 degrees. If the voltage is increased as well, the fan speed should be adjusted accordingly or even set to maximum speed.