Created attachment 166267 [details] UFO test on X11 SUMMARY *** Choosing Plasma Wayland session on Plasma 6.0 will present a desktop that has everything rendered in half of what the screen refresh rate is. *** STEPS TO REPRODUCE 1. In SDDM login screen, choose Plasma (Wayland) session 2. Do anything: move mouse, open apps, whatever, it will look choppy OBSERVED RESULT Any changes on the desktop are choppy EXPECTED RESULT Any changes on the desktop are smooth SOFTWARE/OS VERSIONS Linux/KDE Plasma: 6.0 (available in About System) KDE Plasma Version: 6.0 KDE Frameworks Version: 6.0 Qt Version: 6.6.2 ADDITIONAL INFORMATION $ inxi -F System: Host: LeleChuwi Kernel: 6.6.5-060605-generic x86_64 bits: 64 Desktop: KDE Plasma 6.0.0 Distro: KDE neon 22.04 6.0 Machine: Type: Laptop System: CHUWI Innovation And (ShenZhen) product: MiniBook X v: N/A serial: <superuser required> Mobo: N/A model: N/A serial: <superuser required> UEFI: American Megatrends LLC. v: DNN20A V2.03 date: 12/28/2023 Battery: ID-1: BAT0 charge: 28.9 Wh (100.0%) condition: 28.9/28.9 Wh (100.0%) CPU: Info: quad core model: Intel N100 bits: 64 type: MCP cache: L2: 2 MiB Speed (MHz): avg: 801 min/max: 700/801 cores: 1: 801 2: 801 3: 801 4: 801 Graphics: Device-1: Intel driver: i915 v: kernel Device-2: HYGD-220831-A Hy-Usb2.0-1 MIC type: USB driver: uvcvideo Display: x11 server: X.Org v: 1.21.1.4 driver: X: loaded: modesetting unloaded: fbdev,vesa gpu: i915 resolution: 1920x1200~50Hz OpenGL: renderer: Mesa Intel Graphics (ADL-N) v: 4.6 Mesa 23.2.1-1ubuntu3.1~22.04.2 Audio: Device-1: Intel driver: snd_hda_intel Device-2: HYGD-220831-A Hy-Usb2.0-1 MIC type: USB driver: uvcvideo Sound Server-1: ALSA v: k6.6.5-060605-generic running: yes Sound Server-2: PipeWire v: 0.3.48 running: yes Network: Device-1: Intel driver: iwlwifi IF: wlp0s20f3 state: up mac: c0:a5:e8:40:76:62 Bluetooth: Device-1: Intel AX201 Bluetooth type: USB driver: btusb Report: hciconfig ID: hci0 state: up address: C0:A5:E8:40:76:66 bt-v: 3.0 Drives: Local Storage: total: 476.94 GiB used: 22.99 GiB (4.8%) ID-1: /dev/nvme0n1 model: KPART512GBC2DVT size: 476.94 GiB Partition: ID-1: / size: 455.73 GiB used: 22.99 GiB (5.0%) fs: ext4 dev: /dev/nvme0n1p2 ID-2: /boot/efi size: 299.4 MiB used: 6.1 MiB (2.0%) fs: vfat dev: /dev/nvme0n1p1 Swap: ID-1: swap-1 type: partition size: 12.56 GiB used: 0 KiB (0.0%) dev: /dev/nvme0n1p3 Sensors: System Temperatures: cpu: 27.8 C mobo: N/A Fan Speeds (RPM): N/A Info: Processes: 217 Uptime: 26m Memory: 11.43 GiB used: 3.22 GiB (28.2%) Shell: Bash inxi: 3.3.13 Attached is a proof using UFO framerate test (https://www.testufo.com/), named after the corresponding session.
Created attachment 166268 [details] UFO test on Wayland
`sudo dmesg | i915` is the same for both sessions, however `xrandr --verbose` shows some differences: Wayland ======= Screen 0: minimum 16 x 16, current 1920 x 1200, maximum 32767 x 32767 DSI-1 connected primary 1920x1200+0+0 (0x23) right (normal left inverted right x axis y axis) 141mm x 226mm Identifier: 0x21 Timestamp: 18133 Subpixel: horizontal rgb Gamma: inf:inf:inf Brightness: 0.40 Clones: CRTC: 0 CRTCs: 0 Transform: 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 filter: RANDR Emulation: 1 non-desktop: 0 supported: 0, 1 1200x1920 (0x23) 161.250MHz -HSync +VSync *current +preferred h: width 1200 start 1288 end 1416 total 1632 skew 0 clock 98.81KHz v: height 1920 start 1923 end 1933 total 1978 clock 49.95Hz X11 === Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 16384 x 16384 DSI-1 connected primary 1920x1200+0+0 (0x47) right (normal left inverted right x axis y axis) 0mm x 0mm Identifier: 0x41 Timestamp: 173498 Subpixel: horizontal rgb Gamma: 1.0:1.0:1.0 Brightness: 1.0 Clones: CRTC: 0 CRTCs: 0 1 2 Transform: 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 filter: _KDE_SCREEN_INDEX: 1 panel orientation: Normal supported: Normal, Upside Down, Left Side Up, Right Side Up scaling mode: Full aspect supported: Full, Center, Full aspect link-status: Good supported: Good, Bad CTM: 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 CONNECTOR_ID: 185 supported: 185 non-desktop: 0 range: (0, 1) 1200x1920 (0x47) 136.887MHz +HSync +VSync *current +preferred h: width 1200 start 1240 end 1252 total 1268 skew 0 clock 107.96KHz v: height 1920 start 2125 end 2127 total 2159 clock 50.00Hz No idea if these matter, though.
Same issue for me after updating to Plasma 6 on KDE Neon today. I had no issues prior to the upgrade. My setup is a Dell Precision 7550 laptop (i915) connected to a Dell P2715Q display via HDMI. Using glxgears to test, I get FPS close to Refresh Rate for both screens on X11 but with Wayland, I get roughly half FPS on the external display while the built-in laptop screen is fine.
(In reply to King from comment #3) > Same issue for me after updating to Plasma 6 on KDE Neon today. I had no > issues prior to the upgrade. > > My setup is a Dell Precision 7550 laptop (i915) connected to a Dell P2715Q > display via HDMI. Using glxgears to test, I get FPS close to Refresh Rate > for both screens on X11 but with Wayland, I get roughly half FPS on the > external display while the built-in laptop screen is fine. Quick follow up on the comment I just posted -- I found a fix for my issue! With my original setup (external monitor connected via HDMI), I got refresh rates/fps of 60HZ/60FPS on the laptop screen and 30HZ/15FPS on the external monitor. After some research, I found that I could get 60HZ on the P2715Q with a DisplayPort connection, so I swapped out the HDMI cable and now get 60HZ/60FPS on both screens. Not sure if this would help the OP as his issue occurs with only one display, but hopefully this helps someone with a setup similar to mine.
> Not sure if this would help the OP as his issue occurs with only one display, but hopefully this helps someone with a setup similar to mine. Not directly, but should help developers isolating the potential cause. I also happen to have a USB-C to DP cable which I can use to test on my external monitor, which indeed doesn't exhibit the same problem. High refresh rate (170Hz) even works just fine. So maybe the scope can be reduced to HDMI and DSI connector, leaving DisplayPort out.
This seems similar to what I'm seeing in https://bugs.kde.org/show_bug.cgi?id=482064 On Wayland, the frame rate is half of the refresh rate.
(In reply to Zane from comment #6) > This seems similar to what I'm seeing in > https://bugs.kde.org/show_bug.cgi?id=482064 > On Wayland, the frame rate is half of the refresh rate. Could be, same Plasma 6 Wayland, despite running on totally different platform. So we know it's not platform specific.
*** This bug has been marked as a duplicate of bug 482064 ***
6.0.2 arrives to Neon, and I can confirm it's fixed.