So I went and bought myself a mac pro with a Gforce 7300 as soon as they came out, thinking I would buy an off the shelf ATI X1900 XT and put into the mac myself in order to avoid the delay of getting the computer 6 weeks later. (also, a lot cheaper than buying the card from apple) I went in to the apple store in SoHo NY and asked a very helpful guy there if this was at all possible, and he told me that I should be fine and that the Mac Pro uses a standard PC version of the Radeon X1900 XT. So, I bought a ATI card from ebay which saved me a lot of money....However, here the problem: The ATI card requires additional power than the 300 W the bus can provide, and there IS NO APPARENT way of feeding that power into the card. There's no extra cable in the chassis of the standard configuration Mac Pro so that you could easily upgrade the card. The only solution I can think of is to get a cable that takes power from the 4 pin ATI power connector for the second cd-rom bay, and converts into a 6 pin PCI Express connector. You can find these cables in any well stocked computer store, or online. I wonder though if the ATI X1900 XT upgrade kit that Apple sells has a similar solution and provides an extra cable? Am I stupid, and are there in-fact already supplied means of providing power to the card in there already? I'd love to hear if anyone else has better solution? There seems to be some power outlets on the motherboard for extra SATA discs, and perhaps there is a way to get power from those into the ATI card... I've seen on some forums that people have upgraded their cards in their mac pros, but I wonder how they solved the power problem? Thanks guys.