Hey I am new to this forum so hello. My question is I am planning to add a second 4870 for crossfire. My original card is the 512mb edition. I am thinking of buying another but 1gb this time around and when the time is right swap out the 512mb for another 1gb edition. Is this okay to do and will I have any problems using the 1gb with the 512 until I can afford to have the same amount of memory? Thanks a bunch.