Wow, painless upgrade ... Fry's Electronics had the Apple HD5770 for $249. Removed my older ATI 3870, install the HD 5770, got a MiniPort to DVI adapter for my 2nd Dell 24" (my primary is Cinema HD 30") and voila. Everything worked ... booted into OSX no problems. Motion 4 is smoother with improved FPS and everything seems to work a little faster.
Booted into my Boot Camp drive (Vista x64) and installed the latest AMD drivers from their website Cat 11.6 along with CAP 2 (application profiles) and works perfectly, both monitors. Colors just seem to look better, very fast, excellent!
Highly recommend this video card upgrade to anyone running old MacPro like my 1,1.
I was worried about noise, but it's VERY quiet and Motion 4 and Cinema 4D R12 doesn't seem to stress it much.
Wow, 5 years on my MacPro and I haven't really needed get a new MacPro yet ... think this video card will buy my another 2 years (who knows, maybe the "pro" version of FCP X will be ready by then).
Rob