Runtime power management

I know you were speaking tongue-in-cheek, but if the graphics acceleration is in a different power domain from the frame-buffer raster scanner, then that can be powered down. Likewise, if there's a video decoder core, that too can be powered down.

That's how all those SoCs like OMAP work that go in cell phones and other gadgets. They'll leave the LCD interface up when the display is on so the LCD refreshes, but only power up the graphics and video accelerators when they're needed.