Hey everyone,
I’ve been fighting an issue on my setup where Kubuntu keeps micro-freezing (~1 sec stutters) when moving windows around, dragging the mouse to select on desktop, or sometimes even just using panels/applets. That's honestly making me crazy, I loved Kubuntu but I can't use it the way it is now.
With Nouveau → no freezes, but window dragging and desktop selection feels laggy / not smooth.
With NVIDIA proprietary (550/580) → system runs faster but I get random 1 sec freezes constantly.
It happens on both installed system and live USB.
Things I tried already:
Best regards,
Shiroyama
I’ve been fighting an issue on my setup where Kubuntu keeps micro-freezing (~1 sec stutters) when moving windows around, dragging the mouse to select on desktop, or sometimes even just using panels/applets. That's honestly making me crazy, I loved Kubuntu but I can't use it the way it is now.
- CPU: Intel i5-4460
- RAM: 8GB
- GPU: NVIDIA GTX 960
- Motherboard: ASUS (updated to latest BIOS)
- OS: Kubuntu (latest, clean install tested on live USB too)
- Tried drivers: Nouveau, NVIDIA 550, NVIDIA 580
With Nouveau → no freezes, but window dragging and desktop selection feels laggy / not smooth.
With NVIDIA proprietary (550/580) → system runs faster but I get random 1 sec freezes constantly.
It happens on both installed system and live USB.
Things I tried already:
- Disabled blur/contrast/animations in KWin
- Disabled tearing, strict binding, smooth scaling in KWin config
- Forced XRender backend instead of OpenGL
- Tried both Wayland and X11 sessions
- Updated motherboard BIOS
- Clean NVIDIA installs (nvidia-driver-550 and nvidia-driver-580)
- Tested only with HDMI (unplugged VGA to rule out dual-monitor issue)
Code:
=== Kubuntu GPU Debug Info === ## System Linux shiroyama-allseries 6.14.0-32-generic #32-Ubuntu SMP PREEMPT_DYNAMIC Fri Aug 29 14:21:26 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux ## GPU (nvidia-smi) nvidia-smi not available (maybe Nouveau active) ## KWin supportInformation KWin Support Information: The following information should be used when requesting support on e.g. https://discuss.kde.org. It provides information about the currently running instance, which options are used, what OpenGL driver and which effects are running. Please post the information provided underneath this introductory text to a paste bin service like https://paste.kde.org instead of pasting into support threads. ========================== Version ======= KWin version: 6.3.4 Qt Version: 6.8.3 Qt compile version: 6.8.3 XCB compile version: 1.17.0 Operation Mode: Wayland Build Options ============= KWIN_BUILD_DECORATIONS: yes KWIN_BUILD_TABBOX: yes KWIN_BUILD_ACTIVITIES: yes HAVE_X11_XCB: yes HAVE_GLX: yes X11 === Vendor: The X.Org Foundation Vendor Release: 12401006 Protocol Version/Revision: 11/0 SHAPE: yes; Version: 0x11 RANDR: yes; Version: 0x14 DAMAGE: yes; Version: 0x11 Composite: yes; Version: 0x4 RENDER: yes; Version: 0xb XFIXES: yes; Version: 0x50 SYNC: yes; Version: 0x31 GLX: yes; Version: 0x0 Decoration ========== Plugin: org.kde.breeze Theme: Plugin recommends border size: None onAllDesktopsAvailable: false alphaChannelSupported: true closeOnDoubleClickOnMenu: false decorationButtonsLeft: 0, 2 decorationButtonsRight: 6, 3, 4, 5 borderSize: 0 gridUnit: 10 font: Noto Sans,10,-1,0,400,0,0,0,0,0,0,0,0,0,0,1 smallSpacing: 2 largeSpacing: 10 Output backend ============== Name: DRM Atomic Mode Setting on GPU 0: false Cursor ====== themeName: breeze_cursors themeSize: 24 Options ======= focusPolicy: ClickToFocus xwaylandCrashPolicy: 1 xwaylandMaxCrashCount: 3 nextFocusPrefersMouse: false clickRaise: true autoRaise: false autoRaiseInterval: 0 delayFocusInterval: 0 shadeHover: false shadeHoverInterval: 250 separateScreenFocus: true placement: 5 activationDesktopPolicy: SwitchToOtherDesktop focusPolicyIsReasonable: true borderSnapZone: 10 windowSnapZone: 10 centerSnapZone: 0 snapOnlyWhenOverlapping: false edgeBarrier: 100 cornerBarrier: 1 rollOverDesktops: false focusStealingPreventionLevel: 1 operationTitlebarDblClick: 5000 operationMaxButtonLeftClick: 5000 operationMaxButtonMiddleClick: 5015 operationMaxButtonRightClick: 5014 commandActiveTitlebar1: MouseRaise commandActiveTitlebar2: MouseNothing commandActiveTitlebar3: MouseOperationsMenu commandInactiveTitlebar1: MouseActivateAndRaise commandInactiveTitlebar2: MouseNothing commandInactiveTitlebar3: MouseOperationsMenu commandWindow1: MouseActivateRaiseOnReleaseAndPassClick commandWindow2: MouseActivateAndPassClick commandWindow3: MouseActivateAndPassClick commandWindowWheel: MouseNothing commandAll1: MouseUnrestrictedMove commandAll2: MouseToggleRaiseAndLower commandAll3: MouseUnrestrictedResize keyCmdAllModKey: 16777250 doubleClickBorderToMaximize: true condensedTitle: false electricBorderMaximize: true electricBorderTiling: true electricBorderCornerRatio: 0.25 borderlessMaximizedWindows: false killPingTimeout: 5000 compositingMode: 1 useCompositing: true hiddenPreviews: 1 glSmoothScale: 2 glStrictBinding: true glStrictBindingFollowsDriver: true glPreferBufferSwap: AutoSwapStrategy glPlatformInterface: 2 windowsBlockCompositing: true allowTearing: true interactiveWindowMoveEnabled: true Screen Edges ============ desktopSwitching: false desktopSwitchingMovingClients: false cursorPushBackDistance: 1x1 actionTopLeft: 0 actionTop: 0 actionTopRight: 0 actionRight: 0 actionBottomRight: 0 actionBottom: 0 actionBottomLeft: 0 actionLeft: 0 Screens ======= Number of Screens: 1 Screen 0: --------- Name: VGA-2 Enabled: 1 Geometry: 0,0,1920x1080 Physical size: 820x460mm Scale: 1 Refresh Rate: 60000 Adaptive Sync: incapable Compositing =========== Compositing is active Compositing Type: OpenGL OpenGL vendor string: Mesa OpenGL renderer string: NV126 OpenGL version string: 4.3 (Core Profile) Mesa 25.0.7-0ubuntu0.25.04.2 OpenGL platform interface: EGL OpenGL shading language version string: 4.30 Driver: Unknown GPU class: Unknown OpenGL version: 4.3 GLSL version: 4.30 Mesa version: 25.0.7 X server version: 1.24.1 Linux kernel version: 6.14 Direct rendering: Requires strict binding: no Virtual Machine: no OpenGL 2 Shaders are used Loaded Effects: --------------- shakecursor screenshot outputlocator colorpicker zoom screenedge sessionquit login logout slidingpopups windowaperture slide fullscreen scale squash fadingpopups maximize frozenapp dialogparent windowview tileseditor overview highlightwindow blendchanges startupfeedback systembell screentransform kscreen Currently Active Effects: ------------------------- fadingpopups Effect Settings: ---------------- shakecursor: screenshot: outputlocator: colorpicker: zoom: zoomFactor: 1.2 mousePointer: 0 mouseTracking: 0 focusTrackingEnabled: false textCaretTrackingEnabled: false focusDelay: 350 moveFactor: 20 targetZoom: 1 screenedge: sessionquit: pluginId: sessionquit isActiveFullScreenEffect: false login: pluginId: login isActiveFullScreenEffect: false logout: pluginId: logout isActiveFullScreenEffect: false slidingpopups: slideInDuration: 141 slideOutDuration: 141 windowaperture: pluginId: windowaperture isActiveFullScreenEffect: false slide: horizontalGap: 45 verticalGap: 20 slideBackground: true fullscreen: pluginId: fullscreen isActiveFullScreenEffect: false scale: pluginId: scale isActiveFullScreenEffect: false squash: pluginId: squash isActiveFullScreenEffect: false fadingpopups: pluginId: fadingpopups isActiveFullScreenEffect: false maximize: pluginId: maximize isActiveFullScreenEffect: false frozenapp: pluginId: frozenapp isActiveFullScreenEffect: false dialogparent: pluginId: dialogparent isActiveFullScreenEffect: false windowview: activeView: delegate: animationDuration: 212 ignoreMinimized: false mode: ModeAllDesktops partialActivationFactor: 0 gestureInProgress: false searchText: selectedIds: tileseditor: activeView: delegate: animationDuration: 200 overview: activeView: delegate: animationDuration: 212 ignoreMinimized: false filterWindows: true organizedGrid: true overviewPartialActivationFactor: 0 overviewGestureInProgress: false transitionPartialActivationFactor: 0 transitionGestureInProgress: false gridPartialActivationFactor: 0 gridGestureInProgress: false desktopOffset: searchText: highlightwindow: blendchanges: startupfeedback: type: 1 systembell: screentransform: kscreen: Loaded Plugins: --------------- BounceKeysPlugin KeyNotificationPlugin StickyKeysPlugin buttonsrebind eis krunnerintegration nightlight screencast Available Plugins: ------------------ BounceKeysPlugin KeyNotificationPlugin StickyKeysPlugin buttonsrebind eis krunnerintegration nightlight screencast
Shiroyama