Hi guys. I've managed to run KSP on a 3 monitor setup, both in 1.0.5 and in 1.1. In 1.1 it's even better since the frame rate has drastically increased. Here's how I did it:
I used this to get rid of the borders after disabling the fullscreen mode: http://wiki.kerbalspaceprogram.com/wiki/Startup_parameters. However, this fix only worked for me by adding the popup parameter in Steam. It wouldn't work in the Windows shortcut.
Next, I modified the settings.cfg file. You can find that in the KSP root folder. Open it with a text editor and search for these:
SCREEN_RESOLUTION_WIDTH = 1920
SCREEN_RESOLUTION_HEIGHT = 1080
Modify the values as you wish -> save -> run KSP.
I am currently running in 5440X1080. It's awesome
Snapshot (http://postimg.org/image/5us9pqrjr/full/)
However, on the side monitors things get very skewed up, but it's not much of a problem since most of the action happens on the central one.
