I am currently in the process of selling my gaming pc, in order to buy a mac pro. My old system was an intel core 2 quad, 4GB PC2-6400 low latency, and an 8800 GTX. I've had a macbook for about 18 months now, and i will never go back, hence my recent idea to move my desktop computing to the mac pro. However i am concerned about graphics power in gaming on OS X and on boot camp Vista/XP. I am looking for some advice on what you think the best solution might be, and whether you think the 2 x 2600XT's will be powerful enough for the recent game s in the market (Crysis, COD4:MW). Also wondering if it is possible to use upgrade the mac pro to an 8800 gtx myself, and whether the 2 x 2600XT's needs just simply uses crossfire drivers on bootcamp windows. I am assuming the motherboard does not have an SLi controller, hence the lack of 2 x 8800GT's.