When I played skyrim on my 5770, it ran pretty good on high graphics. But my new 6870 2gb edition gets terrible FPS on high graphics. Battlefield 3 runs fine. But not skyrim. I've seen some benchmarks of the 6870 and they all prove that it can run skyrim great, but something's up with mine, but only on skyr. Any ideas?
It can't be CPU because it ran fine with HD 5770 with the same CPU. It must be drivers. Do you have a spare partition in which you could fresh install windows? Drivers may be corrupted and corrupted drivers are very difficult to get rid of unless reinstalling windows.
Also, what is your power supply and did you connect two 6-pin connectors from your power supply to the graphics card?