Left 4 Dead
Thanks to DirectX 10.1 support, HAWX really likes AMD Radeon cards. With DX10.1 support enabled, the GTX 285 suffers a tough defeat. The HD 4870 X2 ends up about 23% better than the HD 5870.
World in Conflict
World in Conflict seems to like the XFX HD 5870 at most resolutions, leaving Radeon HD 4870 X2 behind by up to 8%. The Geforce GTX 285 scores from 6% to 34% lower than XFX HD 5870.