title kind of says it all...i know that apple only offers the upgrade to 256 mb vram, but is it possible to upgrade after? btw, i'm only asking because i don't know how the quality will be on games? i'm new to mac and mac displays, so if you think 256 mb is plenty for most games (call of duty and other first person shooters) please tell me...thanks for the advice...btw, i have not bought the computer yet, so it will either be an iMac with a core duo, or i may wait for the core 2 duo line to come out...