Summary: Just a slight boost to an already powerful GPU. I have two of these in Crossfire, and can render 4K videos with ease! 4K gaming (with a single GPU) is possible, but seems to prefer games that actually prefer AMD drivers. A lot of the "sponsored by the other guy" games can lag a bit.
Summary: Works great and it also can run games like skyrim on ultra without any lag at all. I have mostly been playing fallout 3 but fallout default graphics are not the great even with ultra turned on.