Video BIOS ??

The video BIOS or firmware contains the basic program, which is usually hidden, that governs the video card's operations & provides the instructions that permit the computer & program to interact with the card. It may contain information on the memory timing, operating speeds & voltages of the graphics processor, RAM, & other information. It is sometimes feasible to change the BIOS (e.g. to enable factory-locked settings for higher performance), although this is usually only completed by video card overclockers & has the potential to irreversibly damage the card. (taken from wiki)