Nvclock allows you to tweak your Nvidia card
under Linux and FreeBSD. It features overclocking, hardware monitoring, tweaking of OpenGL settings, and much more.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
Functionality on all Nvidia cards from the Riva TNT to the GeForce 2 Ultra, better commandline handling, use of getopt_long, and a fix for a GeForce DDR/GeForce2 GTS, Pro, Ultra bug.