Prior to the game's release, the developer put out a benchmarking tool to test your system configuration. It offers a number of different options for utilizing DX9, 10 or 11 code paths. It also offers options for varying levels of HDAO and Shadow Quality. The demo itself isn't very pretty to look at (lots of dirt and dirt-colors), but it does put a beating on your system.
Like the Heaven demo, the demo basically will not run at 5760x1080 using 4xAA, with only 1GB of VRAM.
The new cards provide a noticeable performance jump over previous generations. Widescreen provides a steady performance curve for the current AMD product line. Mid-range cards can hit 30fps at max settings on a single widescreen, with the 2GB cards and CFX configurations passing 60fps.
Eyefinity provides to be a large challenge for any card. The HD 6790 hits around 30fps in a single screen, but Eyefinity isn't an option for this demanding title at DX11, max settings and 4xAA.