I would like to get three monitors working in my G5 quad, so I'll need 2 graphics cards in it. I plan to get an FX4500 for the x16 slot. I will either get another FX4500 or use the current 7800GT in the x8 slot. My questions are: 1. Can the quad power two FX4500s or one FX4500 and a 7800GT? 2. Would the performance of the 7800GT be roughly identical to an FX4500 in the x8 slot?