Patent ID: 7269750

Claim:
A method of managing power in a graphics controller, which is to be coupled to a processor through a bus, comprising: receiving a change indication related to a system power supply; adjusting a first clock, wherein the first clock includes a video clock for a display; adjusting through a voltage regulator, a graphics controller power supply voltage level in response to the receiving of the change indication related to the system power supply; and informing by the graphics controller a Video Graphics Array Basic Input/Output System (“VGA BIOS”) with an indication of a change related to the system power supply, wherein the informing includes requesting a set of one or more preprogrammed available clock rates stored in the VGA BIOS; receiving the set of one or more available clock rates; checking a state of the graphics controller that includes determining whether a 3D engine or 2D engine is active; and choosing a desired clock rate from the set of available clock rates based on the checking.