Multimonitor support on Linux exists, but it’s nothing resembling user friendly—getting it working will require a deep dive into the internals of your window manager.
Here are the options, in order of increasing difficulty:
- Configure the OS to treat all monitors as a single, gigantic monitor. This is relatively easy, but obviously quite limiting.
- Use command line arguments to force X-Plane to allow you to configure multiple monitors. This may still require you to fiddle with your window manager, possibly extensively, in order to get the actual window positioning right. (The OS doesn’t provide a way for X-Plane to position windows such that the window manager won’t move them… so it has to be done manually.)
- Figure out the exact, perfect xrandr configuration that allows X-Plane to configure the monitors directly. This is possible—we have heard some people have figured it out—but we can’t offer guidance or support. The discussion here may help.
We believe #2 is the best option, assuming configuring the displays as a single, wide display won’t suffice. By launching X-Plane with the command line argument –monitor_bounds, you can specify the size and position of each monitor manually, like this:
--monitor_bounds=<left>,<top>,<width>,<height>[<left>,<top>,<width>,<height>, . . .]
So, for two 1080p monitors side-by-side, you’d do this:
For three monitors, you’d obviously add another set of the 4 monitor bound numbers.