We have previously written a guide about overclocking Nvidia graphics cards using Nvclock. Today, we will also talk about the same topic but with a different tool called Nvidia Coolbits. This tool allows to overclock Nvidia graphics cards, but you have to pay attention while using this tool because I don't like you finish this article with a fried board :), so be warned.
If we ananlyze the NVIDIA X Server Settings window, we will note that there is no option for overclocking:
To add the overclocing option, follow these steps:
1. Open the Terminal and edit this file (root permission is required):
sudo gedit /etc/X11/xorg.conf
sudo gedit /etc/X11/XF86Config
2. Replace now the Device section with these new lines:
VendorName "NVIDIA Corporation"
Option "Coolbits" "1"
3. Save the file and reboot your system. Go and check again the NVIDIA X Server Settings window, you will note that a new option is added called Clock Frequencies:
4. Check on "Enable Overclocking", accept the agreement, select 3D Clock Frequencies from the dropdown menu, then click Auto Detect to get optimal GPU and memory frequencies.
5. For my system, I went from 550MHz to 597MHz for the GPU, and from 333MHz to 442MHz for memory. If you are satisfied with the given clocks, then click Apply, or simply restore default settings by clicking Reset Hardware Defaults.
In case of troubles, press quickly Alt+Print Screen + B, and don't go that far in overclocking or you will get a fried board at dinner table :).
Note: Tested under Ubuntu 11.04 and Debian Squeeze, but you can apply it on other Linux-based distros.