wouldnt work well, if at all. a CPU and GPU are built completly different because they are meant to to totaly different things. and the ram wouldnt be fast enough to keep up.
yea, in fact they have different components and structures inside a chip.
have you ever heard of pixel pipelines or vertex shaders? those are inside a GPU, and not inside a CPU. also, system memory is still reading at 128-bit, whereas video memory is at 256-bit.
GPU's are designed for a certain purpose, and even though 2-3ghz would be nice in a gpu, it still wouldnt perform nearly as well because its not constructed right, and wouldn't read 256-bit... and im no genius there could be even more factors... like HEAT lol.
EDIT: also, i dont see how 1gb of ram would help since most games arent even using 512mb of video memory yet. sure theres a few... but not enough to make a video card with 1gb of ram or else they would have already. for instance, windows XP uses like what... 4-8mb of video memory? lol