I own a Radeon HD 6970 and I use the free drivers (Mesa, Gallium3D, all that good stuff). I really dislike Catalyst, as it's glitchy and causes random kernel panics. But I digress.
The main point is, I fired up Big Picture Mode on Steam the other day and in the video settings it says that my card only has 256MB of VRAM. My card very obviously has 2GB GDDR5 memory plastered all over it. What's the deal here?