When testing with Crysis it didn't really matter if we ran the game in DX10 or DX9, the results were much the same on all four graphics cards.
These results actually resemble a lot those recorded using 3Dmark Vantage. The GeForce GTX 260 and Radeon HD 4870 delivered identical performance at all three tested resolutions.
The Radeon HD 4850 was almost 20% slower at 1920x1200, which is not too bad considering it is also over 30% cheaper. The GeForce GTX 280 once again reigned supreme, as it was roughly 20% faster than the GeForce GTX 260 and Radeon HD 4870 graphics cards.