It seems that the new 3DMark is only supporting a horizontal resolution of 2560 pixels, which makes it impossible to use as benchmark for multi monitor setups like AMD Eyefinity or Nvidia Surround.

3DMark detected the higher resolution of 5760x1920 (3 displays) properly:


However, it is only using less then half the resolution:


Here a roundup of all three benchmarks (Ice Storm, Cloud Gate, Fire Strike) running on this Eyefinity system. I zoomed to the center monitor for more details.