yes but edram is more efficient than increasing the number of stream processors in term of aa performance. also they may have "too many" stream processors to that other things like the memory, ROP's or TMU's can't keep up so the extra's are wasted. or they could use it to store something that is being used heavily in the game (certain effects of textures eg. the texture of the ground on in an RTS game) or they could use it to deliver free AF up to 8x or maybe 16x as form what i know it uses less memory than AA. i think EDRAM will be the next big step in architecture. look at cpu's think of how slow they would be without cache.