which video card should I use...
 

upgrading my secondary editing machine to compete with my main. got a new rampage extreme (asus), 12 gigs ram, and a hot new bloomfield i7 975 to run it (main has a i7 965) on the ups truck right now waiting for delivery. now I have an extra radeon 4870 and a nvidia fx4500 laying around so I figured I'd throw one of those in there. I mostly adobe cs3 stuff (waiting a little bit longer for cs4 to mature before I get it). pp, ae, etc... also dabble with maxon cinema 4d. would either have an advantage to use or would I see bout the same performance with either?

tia

Few people have the luxury of having two good video cards to test. Why don't you try both, run some tests and benchmark programs and report your findings. Many would appreciate your testing and hearing about your results.