Unity editor creates flickering on main monitor and reduces framerate

Hi,

For some weeks I've been having a strange issue with Unity (and Maya, 3DS Max and some Unity games): I have a 3 monitor setup (all 1080p, main and right monitor being 144hz), and when I have the unity editor window selected, every 10 seconds or so, my right monitor slows down its framerate and flickers its brightness a bit, and my main monitor just straight up goes dark for 1 second.

If I click on my desktop or chrome or anything else, it stops.

Any ideas what can be happening? I have a GTX 1080 SLI.
Ty!!

 

Do you happen to be using G-Sync? I ran into a similar problem myself with a game and setting it to use Windowed + Fullscreen apps fixed my issue.

 

I've had this same exact problem for a long time too. I have a Dell 144Hz 1440p G-Sync monitor, and a GTX 1070 graphics card. I have the same setting as UnityMaru with both Windowed + Fullscreen apps; it doesn't happen with games so much but definitely when working in the editor I get flickering every few seconds.

 

It's not the 2716DG is it? I have that same monitor and card

 

I have the same Dell 2716DG monitor and was experiencing the same "flickering" issue of the editor. I already had G-Sync enabled for "windowed and full screen" mode - I fixed the problem by changing to "full screen" only mode.

 

Is there a bug/issue filed for this yet? Turning of G-Sync on Windowed mode doesn't count initially a fix to me, more of a workaround. Seems like this issue is bubbling around in various threads still, been around since 2014 or so.

 

It sounds to me more like an Nvidia issue than a Unity issue.

 

For anyone else who finds this via google: You can also work around the issue while leaving G-Sync on, by forcing VSync off in the nvidia settings.

As long as you *don't* have VSync on and G-Sync set to "windowed and fullscreen", you should be fine.

 

I was still facing this issue a year later.

I didn't have the option to set VSync off from the NVidia control panel, but turning off G-Sync for Windowed mode is what worked for me (and having it for full screen only).



(do note, that you might have to restart your PC for it to kick in)

As @Kallex2 mentioned, this feels like a workaround and not a solution, but until such one comes...This will help.

It's worth mentioning that Unity wasn't the only software that I was experiencing flickering with. SourceTree, MSSQLManagementStudio, Visual Studio even - all of them were feeling terrible to work with, prior to adjusting G-Sync. At some point it felt that only the Windows10 native GUI was the only UI (that's not in a video game) handling it okay, so for me, the workaround is a huge improvement already.

So, @UnityMaru , how you got this to work with Windowed + Fullscreen is beyond me, but it does sound like an NVidia issue.

 

Thank you, this solved it for me! (after restarting Unity)

 

I can confirm the same issue on an Samsung Odyssey G7 with a RTX 2080TI. Disabling G-Sync solves the issue or switching to "Full Screen Only". Do note it took an Editor restart to fix switching from "Windowed and Full Screen" to "Full Screen Only" in the Nvidia control panel for Unity to stop flickering.

 

Disabling G-Sync for all windowed applications is a poor way to fix this issue as Games in borderless window mode will be affected too.

The proper way to fix it is to go into Nvidia Control Panel -> Manage 3D Settings -> (Tab) Program Settings, then select Unity 3D (unity.exe) from the list (or add it to the list if it isn't in there) and change "Monitor Technology" to "Fixed Refresh" for this application.

This effectively has the same effect as disabling G-Sync for windowed applications, but it's limited to only this specific application. You can do this with other applications that have this problem as well. It's a typical problem for applications using C# / .net. iirc one of Microsofts Framework UI systems adjusts its refresh rate manually in order to reduce power consumption when nothing changes on the screen. The flicker is caused by the monitor trying to adjust its refresh rate to one that is very low and unstable. By switching it to fixed you're forcing it to display the window contents even if nothing changed inside the window (i.e. it did not request a rerender).

 

I've been running with my dual 2721DGF + 3080 setup for over a year now, and only just started having this flickering issue today.

Setting the Monitor Technology to Fixed Refresh was what fixed it.

 

Had this problem with a 144hz GSYNC on Unity 2021.3.23f1. Even though I have multiple Unity Versions, the NVIDIA Control Panel showed a single "unity.exe". Changing to "Fixed Refresh" worked, after I restarted unity.