I've done some more research and testing. Besides this launchpad, I've opened an issue with NVidia too, as it seems to be a problem with both.
The problems started when I switched from Ubuntu 25.04 to Ubuntu 25.10 but with both the 580.95.05 and 580.105.08 drivers. The problem shows in both GNOME49 and Kwin6.4.5. It seems a problem with the interaction of the NVidia drivers with the compositors. There was a switch from implicit sync to explicit sync in both Compositors. Implicit sync works fine with no stalls but with a performance drop from 60FPS to 24FPS with NVidia drivers on my video application. Setting the NVidia explicit sync environment variable makes it go back to 60FPS but with stalls. What’s different in my viewer (vmrv2) compared to other players: I have TWO Vulkan windows (Viewport and Timeline) open and both are being refreshed at the same time. When the Window is set to Presentation Mode (Fullscreen with no Timeline window or decorations) and the Vulkan presentation mode switches to FIFO, the stalls disappear even with the explicit sync variable. However, as soon as the Timeline window is shown again, the stalls reappear. It seems, to me, a problem of the interaction of the NVidia drivers with the compositors, that was introduced by a change in both compositors from Ubuntu 25.04 → Ubuntu 25.10 AND how nvidia drivers are handling explicit/implicit sync. Some more info: my program works fine with no stalls under XWayland. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/2131651 Title: Vulkan stalls on GNOME 49 (regression from 48) with default nvidia drivers To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2131651/+subscriptions -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
