[SOLVED] Severe full screen flickering


  • Moderator

    @Gwen-Dragon said in Severe full screen flickering:

    Are there special GSync settings in graphics driver or monitor?

    I remember that disabling GSync in GPU driver helped others on Lunix to get rid of flicker.
    And as i could read some minutes ago in your bug report, a Vivaldi dev told the same, to disable GSync in NVidia panel/driver.



  • @Gwen-Dragon said in Severe full screen flickering:

    Do the two monitors have same refresh rate?

    The main monitor (HDMI TV that has the problem) is 60 FPS.

    The two secondary monitors (DVI displays) are 59.950 FPS for whatever reason. I did not set that by hand.


    @Gwen-Dragon said in Severe full screen flickering:

    Are there special GSync settings in graphics driver or monitor?

    No GSync, no FreeSync.


    @Gwen-Dragon said in Severe full screen flickering:

    3.3 Snapshot as Standalone Installation for a test to check if flicker is on 3.3, too

    It does. 😔


    I've noticed that when heavy flickering occurs (only in Full Screen!), then it responds to mouse movement: hover mouse over different elements changes the overlapping patterns. That's with web pages.

    With a full screen video, the overlapping occurs with frames that are ~1s away: characters jitter back and forth. Same with scrolling a web pages: it jitters back and forth for a while.


    @Gwen-Dragon I've filmed a video demonstrating the issue on this very web page (should've started with this...): https://www.youtube.com/watch?v=kx9jvrOQeSw

    Please attach the video link to VB-71118. 🙏


  • Moderator

    @lolmaus said in Severe full screen flickering:

    Please attach the video link to VB-71118.

    You can add this by yourself with reply to report mail of your bug VB-71118 and writing link and information about disabling GSync did not help.
    All what you reply to the mail will get into bug tracker, and you can send attachments, too.

    PS: Sorry, my englisch is very grauenhaft today!



  • I have found the second app that also suffers from the flickering issue: Visual Studio Code, whose GUI is also built with web technologies. Here's the ticket: https://github.com/microsoft/vscode/issues/64383

    Their common solution is to disable GPU acceleration. This is fine for an IDE, but in Vivaldi it causes a severe FPS drop on Netflix, so it's not acceptable.

    Luckily, the VS Code community have identified the culprit: it's V-Sync set to Fast mode.

    My explanation for what is V-Sync and what is Fast mode:

    V-Sync is a technology to prevent screen tearing which happens when GPU FPS does not match monitor FPS: the monitor displays one frame in the top half of the screen and the next frame in the bottom half. V-Sync reduces GPU FPS to be a multiple of monitor FPS (or a multiplier your GPU FPS is higher).
    .
    The true solution to the tearing problem is adjusting the monitor FPS dynamically to match the GPU FPS. Such technology is called FreeSync and G-Sync and requires special hardware inside the monitor.
    .
    "Fast" mode of V-Sync is a know-how of NVIDIA to get rid of tearing with a regular moninor and without sacrificing performance: Fast is only one frame slower than FreeSync/G-Sync. For comparison, regular V-Sync reduces the framerate by 2× or 4× when GPU FPS is lower than monitor FPS (e. g. for a 60 FPS monitor, V-Sync fixes the FPS at 60, 30 or 15, depending on how much your GPU can guarantee). Fast mode is such a simple concept, that I find it ridiculous for it to be novel. V-Sync should've been Fast in the first place, and the 50% FPS drop should've never existed.

    Adding Vivaldi to exceptions and disabling V-Sync has resolved the flickering issue but caused heavy screen tearing when watching Netflix. The solution is to set V-Sync to On (regular mode), which is fine because 99% of video content is at 24 or 30 FPS.

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    PS

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  • Glad you got it sorted out 👍

    @lolmaus said in [SOLVED] Severe full screen flickering:

    I have found the second app that also suffers from the flickering issue: Visual Studio Code, whose GUI is also built with web technologies.

    Yes, it's an Electron app, built on Chromium, just as Vivaldi is.

    https://chromium.googlesource.com/chromium/src/+/master/docs/vscode.md
    https://en.wikipedia.org/wiki/Electron_(software_framework)


  • Moderator

    @lolmaus Thanks for your finding. Useful for others.


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