AMD Radeon HD 4870 X2 2GB Preview - R700 a bit early
Bioshock - AMD comparisons
Bioshock (DirectX 10)
impressive FPS-based game with a great story, Bioshock impresses with
both graphics and its ability to drag you along in the gameplay. It
has both DX9 and DX10 render paths and should make a great benchmark
for graphics cards promising the best of both worlds.
It's not until the 2560x1600 resolution that the 4870 X2 really starts to distance itself from the single GPU HD 4870 card and it is always JUST behind the two discrete HD 4870s in CrossFire mode.