I just bought 3 NVIDIA GeForce 7300 GT, many places say they ar G5 compatible as long it has PCI express slots. Well... mine has them and the cards doesn't work. I hve a quad 2.5 but nothing. I can't find drivers or anthing so the reviews around are not accurate. The Apple web site says Mac Pro only in tiny little gray letters but many reviews say the opposite. Any way, my 2 cents.