you would only get better performance if you use opengl accelerated effects and features… if you are currently are not using opengl (and most prefer not to, it is a little tweaky in ae), then spend you money on more ram, particularly on your quad core (you would like 2gb per processing core when cs3 is released).
also i believe your dual core macs (agp graphics) already have the best cards available. and i don’t think any of the mac agp cards support opengl 2.0 which you would need to get full opengl benefits in ae (things like accelerated anti-aliasing and blending modes). so you would probably never want to use opengl on those macs (who doesn’t want antialiasing???).
on the quad core, you could update to the ati x1900 (there is a special one for the g5 with pci express slots). it does support opengl 2.0 and all the opengl accelerated effects and features in ae. it’s only about $400-500, but i still think i’d spend my money on ram for that machine.
if you still have money to spend and if you really wanted the best opengl performance, you would want to have a graphics card for each monitor. you would only need the best card for the monitor that would be rendering the preview, the other card could be a lesser card (on the agp macs it would have to be a pci or pcix card, since they only have one agp slot). on the quad, you may be able to use the old nvidia card as the second card… although i’m not sure if having to load drivers from two manufacturers would be a problem.
Kevin Camp
Designer – KCPQ, KMYQ & KRCW