This may be a potential erformance improvement for you. We want to disable the desktop mirror by editing a boolean value "engine.ini".

This is an unofficial edit and is therefore unsupported by the Raw Data developers. Please use caution and, as always, create a backup of the file in case you need to revert your changes.

You may either navigate to this directory using the Windows Explorer or simply open the file in NotePad (or another preferred text editor) using command prompt:

Command Line Method:

start NotePad %LOCALAPPDATA%/RawData/Saved/Config/WindowsNoEditor/Engine.ini/RawData/Saved/Config/WindowsNoEditor/Engine.ini

Windows Explorer Method:

%LOCALAPPDATA%/RawData/Saved/Config/WindowsNoEditor/Engine.ini/RawData/Saved/Config/WindowsNoEditor/Engine.ini


Figure 1: Config directory

Try toggling off the SteamVR mirror:

[SteamVR.Settings]
WindowMirrorMode=0


Figure 2: Engine.ini after edit.

Boolean values can either be 0 (false) or 1 (true). By changing the WindowMirrorMode value to 0, or false, we disable the mirrored image on the desktop. We will still have a window that needs to stay visible for the game to work.

The game will load. The mirror window will be a black screen but, as long as you're not on some Optimus laptop GPU, you should still see the game in your HMD. Do not minimize the window as it will turn off the HMD display as well. However, because you aren't wasting precious resources rendering the desktop mirror, you may see a performance increase.

Your mileage may vary!

-Ghostlight