The reason I asked is that I bought my machine with a 512 upgrade which kept alernating between being 256 and 512. I took it back to my dealer who said all he had was 2700 as Apple were out of stock of 2100 cards. He took my card out and put it back in again and it seems so far to be staying at being 512. Must've just been seated badly. And now when I check, I see the card has been 2700 all along. My dealer said something about that might be why it didn'r read right because of a switching problem which I think is like most of his computer information - completely wrong and crap.