Bug 515264

SUMMARY
The "Present Windows" and "Overview" effects exhibit a short, but noticeable delay when they're triggered on a multi-monitor setup. The effect itself is smooth and lag-free, it's just the initial delay before it triggers. Encountered on Arch, CachyOS and NixOS on differring KDE versions.

STEPS TO REPRODUCE
1. Set up CachyOS
2. Connect a screen or two
3. Bring up System Settings > Screen Edges
4. Set one edge to "Present Windows - All Desktops"
5. Bring up System Settings > Shortcuts > Window Management
6. Assign a keyboard shortcut to "Toggle Overview"
7. Trigger "Present Windows" effect by touching screen edge with mouse and/or Overview effect via keyboard shortcut

OBSERVED RESULT
There's a noticeable delay when triggering the Window Overview or Present Windows effects in KDE with 2 or more screens connected to the PC.

Video showing virtually no delay on single-screen setup (2026.01.28):
https://www.youtube.com/watch?v=apaH-sXR0ok

Video showing noticeable delay on 3-screen setup (2026.01.29):
https://www.youtube.com/watch?v=s6Ps23dUUUs

EXPECTED RESULT
The effect should trigger instantly.

SOFTWARE/OS VERSIONS
Operating System: CachyOS Linux
KDE Plasma Version: 6.5.5
KDE Frameworks Version: 6.22.0
Qt Version: 6.10.1
Kernel Version: 6.18.7-2-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 16 × 12th Gen Intel® Core™ i9-12950HX
Memory: 64 GiB of RAM (62,4 GiB usable)
Graphics Processor 1: NVIDIA GeForce RTX 3080 Ti Laptop GPU
Graphics Processor 2: Intel® UHD Graphics
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: ROG Strix G733CX_G733CX
System Version: 1.0
Nvidia driver: 590.48.01

More details about my graphics card: https://discuss-cdn.kde.org/uploads/default/original/3X/c/1/c1fb4c05503e2972e42f5323e6a2b16806d6afa0.png

ADDITIONAL INFORMATION
- This issue is virtually nonexistent when only one screen is connected and becomes more pronounced the more screens you have set up
- Originally reported on the KDE forums: https://discuss.kde.org/t/noticeable-delay-to-trigger-window-overview-effect-in-cpu-power-save-mode/42351
- User akshath notes that the delay is less bad when CPU is in performance mode
- Same user also reports: "CPU usage of kwin_wayland is high at first, and it causes delay. After that, GPU takes effect work."
- The above Software/OS specs are mine, here are the specs reported by affected forum user kavelach:

Operating System: NixOS 25.11
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.20.0
Qt Version: 6.10.1
Kernel Version: 6.18.0 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 32 GiB of RAM (31,2 GiB usable)
Graphics Processor: Intel® UHD Graphics 620
Manufacturer: LENOVO
Product Name: 20KN001QPB
System Version: ThinkPad E480

- akshath's specs: Arch, kwin 6.5.3, plasma 6.5.3. Double monitor, iGPU