Questions about video cards with an Apple G4

Hello everyone, I currently do not know much about Apple/Mac computers so I came here to ask some more experienced users.

A friend of mine bought a video card off of ebay, it was a nvidia geforce 5600. Are G4's compatible with this or is he just doing something wrong? Any information would be grateful!

G'day and welcome to the Forums.

Firstly you need Mac video cards to run on your Power Mac. PC cards will NOT function unless they are 'flashed', a term describing changing the ROM which is quite complicated and on occasions fries the card. Here is a link that explains the process:-

http://forums.macrumors.com/archive/index.php/t-15123.html

You do not give the machine model or operating system, however an ATI Radeon 9000 Mac Pro works in all 2X and 4X AGP Macs, and if you are using Leopard, a 9600 Mac Pro would be the go.