It has been a while since I've been able to get one of my ~4K videos up, Deus Ex is a action / stealth based game, it natively supports multi monitor resolutions and if you can get it to detect that your using Eyefinity it can even centre the HUD for you. Once again if your monitors width is larger then 1920 pixels and you have lots of bandwidth, set the quality to original and play the video in full screen for a much higher quality.
Direct Video Link: http://www.youtube.com/watch?v=aZ8ZUiL6W2E
Channel Link: http://www.youtube.com/user/n11skid
Copy paste of video description:
Deus Ex - Human Revolution on the PC, Original resolution was 5040x1050 aspect ratio of (48:10). If you are running a resolution with a width higher then 1920 (30'' monitor or multi monitor) set quality to original and view in fullscreen.
The video is from game launch, skipping the first part of the game and showing a section of the second part. I've also put my usual annotations about how the game preforms with three screen.