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Looking Glass - Triage



+1 also noticed this. Haven’t had time to bisect specific commit.


Does this occur when you use the EGL renderer?

looking-glass -g egl

Edit: Scratch that… There were some changes made to improve mouse sync with the client, one of which is to always feed back the mouse position even when DXGI doesn’t capture it.

Let me have a bit of a dig into the changes and see if I can spot why this might be occurring. If you could provide details on your mouse setup it would help.

One of the changes pushes mouse updates into a queue to ensure they are not missed, as a dropped mouse update may cause the cursor icon to be incorrect, or visible/invisible when it shouldn’t be. If this queue backs up it could explain the behaviour you’re seeing. I may need to take another approach and accumulate the updates instead of queuing them.

Please also provide the output from the client.


I just pushed in an update that implements cursor update accumulation, this should both be faster and will prevent the cursor lag you were experiencing. This is a host only update, no need to rebuild the client.

Edit: There were still some bugs in this code that have been fixed, be sure to fetch the latest version.


Much better after the recent changes. :slight_smile:


Massive frame rate drop when I run the Linux client. (Host and VM are using A11)

I’m testing running Counterstike GO on a Windows VM. I can get 180 fps in one particular area of the map (this is with only the Windows LG client running) but as soon as I run looking glass on my Linux host the frames drop down to around 40.

I have passed my kb, mouse and GPU to Windows. I am not running a Spice server (-s option). I use Virt Manager and here is my libvirt config (

I have no clue what the issue is. Hopefully someone has an idea?


Just to be clear, the windows executable is the host, not the client.

Are you running CS:GO windowed or dedicated full screen?
What is your Guest GPU?
Are your drivers up to date?
What resolution are you running?

I have noted this framerate drop also in certain applications, and alt-tabbing in/out resolves it. If that corrects the problem it’s a driver issue.


The Windows exe is the host (looking-glass-host).
My guest GPU is a GTX 1060 3GB. Host is Intel UHD 630.
Drivers are dated September 399.24 (latest from Windows).
1080p full screen (not windowed).

But even the desktop looks like crap when using looking glass. I don’t see any input lag but there is ghosting when dragging windows around and I see some distortion, when moving windows, horizontally across the screen about 25% up from the bottom.


Screenshot/photo please?


I’m not able to capture these effects in a screenshot.

I think ghosting is the wrong term. I mean that the desktop frame rate seems really low so that when moving a window around the screen, it looks very laggy.

As for the line - I will try to explain better. Say there is an invisible line, 25% up from the bottom of the screen that runs the full length across it.

I move a window from the right to the left of the screen with the vertical middle of the window on this line. I can see that the bottom half of the window is slightly ahead of the top half by a few pixels.


This is a vsync artifact, you’re seeing two frames at once.


The vsync artifact isn’t a big deal but what can I do about the low fps? I just installed the newest drivers from Nvidia but it hasn’t made a difference.


This is the first time there has been a report of the DXGI capture causing a client side framerate drop of such significance. Are you running any other capture/streaming software perhaps?


Nope, nothing.


I am sorry, about the only suggestion I have at this point is to wait until A12 as quite a lot has changed that may have already fixed the issue you’re encountering.


When is A12 due to be released?


There is no scheduled timeline, it’s as I get free time to work on the project.


I’m running Arch currently but I’m going to install Debian and see if I have better luck. I’ll report back.


It is extremely doubtful that it will change anything as the slowdown is in the guest, not the host. It slows when the client runs as it’s not capturing until the client is running.


Do you think there could be an issue when I compile the Linux client? It’s just that there is a rather messy output that I don’t understand.

I used to get the dependencies as the Debian ones don’t translate.

When I run make the output is:

Edited by gnif: Removed useless noise.


No, again, as stated above it is not an issue with the Linux client. The only thing that can slow down the game’s FPS is if there is an issue with the catpure itself, which is in the host executable.