I have been using Nvidia my entire life and have never put a ATI card in my personal gaming rig before. I like Nvidia and I also my want to take a CUDA coding class in the next year. I'm not worried about heat either my case keeps anything cool. I'm worried though that my PSU will not handle the GTX 470's power or amperage needs. Thus I find the HD 5850 would be a much "Safer" bet in that department. I'm really only using this rig to play Valve based games like HL2, StarCraft 2, and Diablo 3 when it come out.
Do you guys/gals think that my computer can run a single GTX 470? I have looked all over for reviews of both and found a lot of conflicting info on the power usage of the GTX 470.