Re: nVidia and ATI FLOPS difference?
There a lot more to the cards than just the maxium possible flops it can calculate.
Even if one wouldn't think about textures, rasterizing and such and only the flops, there are architectural differences on the cards which make them better in some cases and worse in some.
Lets just say that G4xx series is easier to get calculation efficency when compared to a Atis GPUs.
When job is one that Atis GPU likes and is properly coded it will be faster, but not all jobs fit the GPUs that well and in those cases G480 should win.
If you want to know more, read all the publications about GPU architectures read discussions on subjects in proper forums and you should get a the basic idea.