Q: thanks alot for answers
A: No. if you were to buy the 4850 1gig version it would perform exactly the same as a 4850 512 mb, the only difference would be the 4850 with 1gig would be able to run higher resolutions better. Also, 2 4850 512mbs in crossfire would nearly have double the performance of a 4850 1gig. Due to there being 2GPU's VS 1GPU.