If you have Nvidea graphic card you may know that Nvidia’s video driver package has an overclocking component to it, but it is disabled by default and can only be re-enabled by editing the registry manually or with a file.To activate overclocking in Nvidia cards follow next steps:

1. Open REGEDIT
2. Navigate to ‘HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\NVTweak’
3. Create a new DWORD value called ‘Coolbits’ and give it a value of ’3′
4. Reboot.

This solution feature creates a ‘clock frequency’ page in the Nvidia display software.

There you can adjust the GPU and memory clock speeds. Before applying allow the drivers to test them. This is not a guarantee of successful overclocking, just a test for basic stability. You can also use the ‘auto detect’ button, which will determine the recommended level of overclocking. Use of this feature generally results in slightly conservative settings, but it makes a good reference point. Changes will be applied automatically upon pressing ‘ok.’

Possible implications:
Overclocking the card produces more heat, and eventually you will reach a point where the safeguard (the graphics processors have a thermal safeguard) kicks in and your benchmark scores will drop perceptibly no matter how much more you overclock the card. The trouble is, even if you crank the card back down to more conservative settings once you have reached this point, chances are the safeguard will still be in effect until the card gets a proper chance to cool down a bit (by rebooting, for example.) so you must try the adjusting again.

Once you have found an optimal level, use the ‘apply settings at startup’ checkbox so you do not have to reenter the settings after a reboot.

Tags | Graphic, Hardware, Speed Up, Tips and Tricks, Video, Windows