The short answer is: As many as your video card(s) and display drivers can handle.
As we'll detail in this post, we were recently able to re-test DisplayFusion with 11 monitors. We've also had customers report that DisplayFusion works well in their 12 monitor setups.
Note: Some cards have more outputs than they can physically enable at one time, which cannot be worked around using software (i.e. many cards have 3 outputs, but only 2 can be enabled at one time).
All of the DisplayFusion features worked great in the 11 monitor setup.
Certain actions, such as applying the wallpaper settings, or reloading the taskbars take a bit longer than on a 2 or 3 monitor setup, but that's to be expected, as there's a lot more work to be done behind the scenes when handling that many monitors. See the following screenshots for what the various configuration screens look like with 11 monitors attached.
There are some bugs in Windows when using this many monitors. The Windows Screen Resolution settings window doesn't put an ID on any monitors with an ID higher than 10. The DisplayFusion Monitor Configuration shows the monitor ID on all monitors, including ones with IDs higher than 10. Additionally, the built-in Windows Screen Savers crash (regardless of whether you configure them using Windows, or DisplayFusion) when running more than 9 monitors.
To prevent the Screen Saver crashes from showing up in DisplayFusion, we've added a check that will prevent the Windows built-in Screen Savers from being selected in the DisplayFusion Screen Saver configuration on systems that have more than 9 monitors enabled.
While all of the DisplayFusion features are great with 2 or more monitors, we found the following features to be especially helpful when using 11 monitors:
Monitor Configuration: The Windows Screen Resolution settings can be a bit cumbersome to use, especially when enabling and arranging many monitors. Many of the steps require you to apply the settings before performing the next step. For example, you can select each monitor to be enabled, but then you must apply the settings before re-arranging them to the correct layout.
The DisplayFusion Monitor Configuration feature not only allows you to enable and arrange the monitors before applying the settings, but it also allows you to save different monitor layouts as Monitor Profiles, so that they can be quickly applied with a few clicks in the future.
Monitor Selector and Custom Functions: When you've got 11 monitors, being able to specifically select which monitor an application should move to becomes a very handy tool. Using DisplayFusion's Functions, you can achieve this in a couple of ways.
Using the Move Window to Different Monitor Function, which shows a monitor selector, you can choose which monitor the application should move to when running the Function.
Alternatively, you can create custom Functions that automatically move the application to a specific monitor when the Function is run, and skip the step of having to choose a monitor each time you want to move the application.
Mirror Monitor/Window Function: When running a system with many monitors, it's entirely possible that you may have monitors located in different physical areas, outside of your viewing range. There are two DisplayFusion Functions that can help in this situation.
The Mirror Monitor Function will mirror the output of the selected monitor into a separate window that can be resized and moved to any other monitor. The Mirror Window Function will do the same, but it will use the output from the selected application.
