Looking Gass and Variable Refresh Rate

Operating Systems & Open Source Looking Glass
1

I’ve been wondering to what extent Looking Glass and variable refresh rates work together, and could work in the future. Freesync between the game and host screen is obviously a hard (impossible? possible with IDD driver?) feature, but I’m wondering about the middle ground.

Let’s say you enabled Freesync on the Guest VM to a screen, enabled Freesync on the host, while running Looking Glass under Wayland. From what I understand the frame is captured by DXGI as soon as its rendered, which will then get sent to the host, and displayed by Looking Glass. Would the rendered game have the some of the latency and timing benefits as native Freesync?

I’ve done a little bit of testing, and from what I can see my screen’s framerate monitor (yay gaming screen) roughly matches the ingame FPS in the above setup. So it seems in principle to be working. However I have no equipment to test actual latency.

Cheers

2

It’s up to your compositor and in turn your display server to manage variable refresh.

LG only draws when there is a new frame to draw, or you move the mouse, by nature it is already variable refresh rate.

3 Likes
3

Some games allow you to set the frame rate to vsync. What exactly does that mean, if looking glass only draws when there is a new frame to draw?

4

Looking glass is an implementation of the KVMFR protocol.

This video explains how it works: