One of the best received gaming titles on both console and PC for
2009, Batman: Arkham Asylum is an impressive game both visually and in
terms of design. 

Batman: Arkham Asylum Test Settings

One interesting note: Batman (personally) doesn't allow setting AA
levels in-game for AMD graphics card but DOES for NVIDIA GPUs.  We
instead enabled AA in the AMD Catalyst Control Panel where noted.

A trend that I think you will see repeated throughout our CrossFireX testing today is that adding in that third card really won't be making a big difference until you hit that 2560x1600 resolution.  Here in Batman: Arkham Asylum, you'll see at 1680x1050 we saw a 71% performance boost adding in the second Radeon HD 5870, we only saw an additional 15% performance gain adding in the third.  At 2560x1600 that changes a bit: 84% boost moving to two cards and a healthy 43% performance increase adding in that final card.