I can test that with my 5770 once I have Afterburner set up. I've never seen it reach 1GB on my card with my really intense Wind Waker settings (5xIR 4xAF 2xAA + hi-res textures), so it probably doesn't go far enough to need more than 1GB.
in a perfect world we would all be piles of sand with no ability to form coherent bodies of body