GTX 480 is twice as fast than HD 5870 ! (in Unigine)
 

Nvidia's GTX 480 ends up faster than HD 5870 in some cases and according to Nvidia it is the fastest GPU on the market, or to be precise, it will be faster than the HD 5870 once it finally shows up.We must note that we can confirm that it does happen in some cases, as Nvidia is still keeping the performance numbers for itself as it wants to keep AMD at its toes. Nvidia reps are pretty sure that AMD is still tapping in dark when it comes to Fermi.

http://www.fudzilla.com/content/view/17889/34/