I have 2 Sapphire X1650 Pro PCI Express cards and I just ended up with a decent powermac g5 I was wondering if these cards will work, I've tried to find an answer with no luck any one know if they will work even if its just one? And if so does it offer an improvement over the factory card?
If the cards are meant for a PC they will most-likely not work in your Mac. I believe the card's BIOS would need to be flashed to be Mac compatible...especially since you don't have an Intel based Mac.
Since we don't know what the "factory card" you have is
we can't say if a Sapphire X1650 would be better (if you were to somehow get it working).