Configure the IDD
Right-click the Looking Glass (IDD) icon in the Windows notification area and select Open configuration. The icon and its tooltip also show whether the driver is using GPU acceleration or software processing.
Display modes
The mode list controls the resolutions and refresh rates that Windows may use for the Looking Glass monitor.
Select a mode to edit its width, height or refresh rate, then select Update.
Select <add new>, enter a mode in the fields below the list and select Update to add it.
Select Delete to remove the selected mode.
Select Load default to replace the working list with the standard modes.
Enable prefer on the mode that Windows should prefer. Only one mode can be preferred.
Refresh rates may contain up to three decimal places. For example, enter
119.970 rather than rounding it to 120 Hz. Accepted values range from
23.900 Hz to 1000.000 Hz. Width may range from 640 to 16384 pixels and height
from 480 to 16384 pixels.
Edits to the mode list are not applied immediately. Select Save & reload driver when the list is ready. This saves the list, removes and recreates the virtual monitor, and can make the display blink briefly. Revert discards unsaved mode and default-refresh changes.
Default refresh
Default refresh is used when the client asks the IDD to create a dynamic resolution. It also supplies the refresh rate when Load default rebuilds the standard mode list.
Changing this value does not rewrite refresh rates already saved in the normal mode list. On reload, an existing dynamic mode keeps its resolution and adopts the new default refresh rate.
The client option win:setGuestRes enables automatic dynamic resolution
requests when the client window changes size. The default is enabled when the
server in the guest supports it. Press the client’s escape key together with
= to request the current window resolution manually.
Preferences
- Make LG the only monitor
Makes the Looking Glass display the only active Windows monitor. This is enabled by default and the helper restores the topology when required. Disable it if you intentionally use other guest displays at the same time. Disabling it stops future enforcement but does not automatically restore displays that Windows has already disabled.
- Disable no GPU warning
Suppresses the notification shown when the IDD has fallen back to software processing. It does not enable GPU acceleration or change the active adapter.
- Force full direct frame copies
Works around GPU drivers that corrupt partial D3D12 copies into the shared transport heap. When enabled, the GPU copies every direct frame in full; readback/indirect transfers continue using partial damage copies. This can substantially increase GPU and shared-memory bandwidth, so leave it disabled unless you encounter corruption. Changing it requests a driver reload.
- Force indirect copy
Disables direct D3D12 access to the shared transport heap and instead copies each frame through a CPU-mapped readback resource. Enable this only to work around a GPU driver that corrupts direct transport writes: it adds a CPU copy and significantly reduces throughput. It takes precedence over the direct-copy preference and requests a driver reload when changed.
Unlike mode-list edits, preference checkboxes are saved when clicked.
Software processing
If no suitable Windows render adapter is available, the IDD can use software processing. This provides a display but is slower, cannot provide predictable high-rate cadence and is limited to SDR. Check the IDD log to see which render adapter was selected and whether software processing is active.