In 2005 we had featured several articles on the state of NVIDIA graphics card overclocking under Linux. In early 2005 the only option for Linux users was NVClock. The open-source NVClock was started by Roderick Colenbrander in 2001 and since then has been evolving. However, coming out in June of 2005 from the NVIDIA camp was CoolBits support for their alternative operating system drivers. This feature was certainly revolutionary for Linux gamers and enthusiasts. However, after a recent inquiry on the Phoronix Forums, this article has been constructed to spell out a few things about overclocking software available for GNU/Linux.
Since its inception, NVClock has evolved quite a bit. At this time there is not only the command-line interface but also GTK and Qt versions. The latest version of NVClock (v0.8 Beta 2) as well as the CVS version support overclocking the NV GPU core and video memory. Other features include card information, OpenGL/display settings, hardware monitoring of both fan speeds and die temperatures, fan speed control, pipeline modding (GeForce 6 series), and PCI id modding. The NVClock does have its own core backend for overclocking, but now this utility is also able to use CoolBits. While it has been a few months since the last beta release (CVS access is available), NVClock supports most NVIDIA GeForce FX, 6, and 7 series graphics cards.
Since the NVIDIA 1.0-7664 display driver release on the first of June last year, their Linux drivers have supported CoolBits. To enable CoolBits, Option "CoolBits" "1" needs to be added to the nvidia device section of the xorg.conf. The Linux version of CoolBits is similar to the Windows version, which allows you to overclock the GPU core frequency as well as the memory. An auto-detect feature is also available, which attempts to automatically find the highest stable frequencies. After enabling CoolBits the various settings are available from the NVIDIA Linux Control Panel. This overclocking is handled through the NV-CONTROL X extension and only works with the GeForce/Quadro FX and newer.