Display layout configuration in Windows

The general approach to rendering to multiple displays in Windows is as follows:

1. export-edid-windows
2. force-edid-windows
3. configure-mosaic-windows
4. reset-desktop-scaling-windows
5. disable-screensaver-windows

Since the NVIDIA Control Panel is unstable on large video walls, we use the Mosaic Utility command-line tool instead to create Mosaic groups and specify display layout. Using this tool also has the added benefit that the display layout can easily be stored in a Windows batch file for easy recovery later. This is very helpful because Windows itself is also quite unstable regarding its display layout and there\'s a high chance it will eventually lose the configuration due to Windows update or some other change.

Tip

For examples of certain configurations, see video-wall-examples.

Export display EDIDs

Tip

You can download a pre-exported EDID for MT557D in video-wall-examples.

In order to create a stable display configuration, we need to acquire the EDID information of our displays and force the GPUs to think the displays are always connected.

There are many possible reasons for unstable display layout such as issues with cables (quality, length) or misbehaving video extenders. With the exported EDID information, we can force the GPU driver to think the physical connections to the displays are always present, even when they are not or there is a problem automatically detecting them.

Warning

You should always export and force the EDID information for a stable display layout.

Launch NVIDIA Control Panel and navigate to Workstation > View system topology on the left panel:

View system topology in NVIDIA Control Panel.

Then on the right panel, find your connected displays and click on the EDID link to open Manage EDID dialog:

Export EDID tab in Manage EDID dialog in NVIDIA Control Panel.

In the Export tab of Manage EDID dialog, select each display you want to export the EDID for and click Export EDID.

Save each EDID to a file that you recognize later. For example, if using MultiTaction Decca displays, you can use a filename like mt557d-edid.txt.

Tip

If you are using multiple identical displays, you can export EDID information from only one of them and re-use the same exported EDID for each identical display to save some effort.

However, if you have multiple different displays, make sure you don't mix the EDID from one display model to another. If in doubt, you can always export the EDID separately for each display.

Next, we force the EDID to be loaded from the exported file(s) to each GPU output.

Force display EDIDs to each GPU output

Still in the Manage EDID dialog, select the Load tab. First, select an EDID file you exported previously. After selecting the file, choose one or more GPU outputs below to which to apply the chosen EDID for and click Load EDID:

Load EDID tab in Manage EDID dialog in NVIDIA Control Panel.

Once the EDIDs have been forced, we can proceed to set up Mosaic groups.

Configure Mosaic groups

Our aim is to create one Mosaic group per GPU using the Mosaic Utility command-line tool. To begin, open a Command Prompt and navigate to the folder where you have downloaded Mosaic Utility.

To start from scratch, run the following command in to disable everything except one display:

configuremosaic disable

We then use the tool to define the Mosaic groups, display layout and bezel compensation with a single command. As an example, to configure a 5x1 wall with three displays on first GPU and two in the second:

configuremosaic set rows=1 cols=3 out=0,0 out=0,1 out=0,2 rotate=270 bezel=8,0 nextgrid rows=1 cols=2 out=1,0 out=1,1 rotate=270 bezel=8,0

The order in which your arguments appear in the command defines the layout. For example, out=0,0 out=0,1 out=0,2 defines the layout as left to right for GPU=0 outputs 0,1 and 2. If you would want to reverse the order, you would just define out=0,2 out=0,1 out=0,0.

Tip

You can use configuremosaic --showindices query gpu to see the index numbers of each GPU.

Or you can use the identify button in NVIDIA Control Panel to see the outputs on each display.

Also note that changing the Mosaic groups is a slow operation that will take several seconds, so be patient.

For help with the tool, see:

configuremosaic help

Test your layout by moving the mouse cursor around and verify the correct display layout. If you need to make adjustments, just use the configuremosaic tool until you are happy.

Hint

If you make a mistake with a configuremosaic command and get an error, you must run configuremosaic disable to reset the configuration before trying to proceed further.

Next, we need to make sure the desktop scaling is 100% on each group.

Reset desktop scaling to 100% on each Mosaic group

To ensure correct rendering in many applications, the display scaling must be set to 100%. Open the Display settings by right-clicking on the Windows desktop.

Select each of your (virtual) displays that correspond to Mosaic groups and under Scale and layout change the size of text, apps, and other items to 100%:

Reset desktop scaling to 100% under Scale and layout.

Do this for each display in Display settings.

Finally, we need to disable the screensaver to prevent the displays from going to sleep.

Disable screensaver

Open Power & sleep settings in Windows. For both Screen and Sleep, select Never to prevent the displays from going to standby or the PC going to sleep:

Disable screensaver under Power & Sleep settings.

Next, continue to configure-graphics-coordinates.