I don't know of any way to do this. You can switch to your onboard graphics but I don't think you can completely power down your graphics card without entering the BIOS. You can usually get software to manually control the fan on your graphics card though. I do this when listening to music so it doesn't interfere with my open headphones. At 25% it's just about silent. I also use one of those self-contained water coolers for my CPU for the added performance and reduced noise.
Edited by Stalker81598 - 7/11/13 at 2:45am