Bug 494780 - Performance Degradation on Nvidia (Hibrid) HDMI Output with Triple Buffering Disabled (Fedora 40, KDE Plasma)
Summary: Performance Degradation on Nvidia (Hibrid) HDMI Output with Triple Buffering...
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: general (other bugs)
Version First Reported In: 6.2.0
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-10-14 22:07 UTC by Jorge Durán
Modified: 2024-10-19 19:54 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
Example of moving a screen creating jerky movement and high usage on Nvidia GPU (192.06 KB, video/webm)
2024-10-14 22:07 UTC, Jorge Durán
Details

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Description Jorge Durán 2024-10-14 22:07:31 UTC
Created attachment 174824 [details]
Example of moving a screen creating jerky movement and high usage on Nvidia GPU

Summary: There is noticeable performance degradation when using an external monitor connected via the Nvidia HDMI output on hibrid configuration AMD + Nvidia laptops . The GPU usage spikes to 100% when moving windows on the external monitor and moving windows around. This issue did not occur before upgrading to KDE Plasma 6.2.

Steps to Reproduce:

Connect an external monitor to the Nvidia HDMI output.
Move windows around on the external monitor.
Observe GPU usage and performance when moving windows.
Expected Results: Smooth performance without excessive GPU usage.

Actual Results:

GPU usage reaches 100% (as observed via Btop++) when moving windows, causing sluggish performance and jerky movement.
The issue is specific to the Nvidia HDMI output. When using the AMD integrated graphics to connect the monitor, performance is smooth and the GPU use remains minimum.
This performance degradation did not occur prior to KDE Plasma 6.2.
System Info:

Operating System: Fedora Linux 40
KDE Plasma Version: 6.2.0
KDE Frameworks Version: 6.7.0
Qt Version: 6.7.2
Kernel Version: 6.11.3-350.vanilla.fc40.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7840HS w/ Radeon 780M Graphics
Memory: 30.6 GiB of RAM
Graphics Processor: AMD Radeon 780M + Nvidia HDMI Output
Laptop Model: Victus by HP Gaming Laptop

Could be related to the issue #494407 as affects the same system configuration.
Comment 1 Evert Vorster 2024-10-15 05:27:18 UTC
Additional information:
This seems to be Wayland related, as there are no performance issues on an X11session.
Comment 2 Nick H 2024-10-15 06:09:47 UTC
SUMMARY:
After updating to Plasma 6.2 in Garuda Linux moving windows became slow, jerky and created high discrete GPU usage (

STEPS TO REPRODUCE:
1. Have an external Monitor (connected via USB-C Display Port)
2. Login to Wayland Plasma desktop session.

OBSERVED RESULT:
- Window movement slow and jerky on external monitor with discrete Nvidia GPU usage 50-80%.
- On inbuilt monitor very smooth with discrete Nvidia GPU usage of 15-50%.

EXPECTED RESULT: 
-See second point under Observed Result.

SYSTEM INFO:
Operating System: Garuda Linux 
KDE Plasma Version: 6.2.0
KDE Frameworks Version: 6.6.0
Qt Version: 6.7.3
Kernel Version: 6.11.3-zen1-1-zen (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800H with Radeon Graphics
Memory: 15.0 GiB of RAM
Graphics Processor: AMD Radeon Graphics (with Nvidia 3060 M discrete)
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: ASUS TUF Gaming A15 FA506QM_TUF506QM
System Version: 1.0

ADDITIONAL INFO:
Added this to show it's not just HDMI but also Display Port (usb-c) monitor connections affected.
Comment 3 Jorge Durán 2024-10-19 19:54:37 UTC
Seems to be fixed on the 6.2.1