So I’m running the KDE Plasma edition of Fedora 29 with the 418.56 driver as well as dual mixed 4K monitors (LG 32UK50T (primary), Acer XB280HK (secondary)) at 200% scaling, and without Force Composition Pipeline on, I get quite a bit of screen-tearing even when the monitors are set at 30hz. So to get around that, I enable the Force Composition Pipeline; on the secondary Acer monitor it works fine, but on my primary LG monitor, it forces the desktop to run at 30fps (Checked with KDE’s FPS tool) thus making the monitor feel like it’s running at 30hz even though I triple checked with the nvidia-settings, the kde settings, and with xrandr to make sure the monitor is running at 60hz. The things I have tried in order to fix it: Changing the rendering backend for the KDE compositor, changing the tearing protection on the KDE compositor, setting the monitor refresh rate to 60hz, changing the sync to vblank/allow flipping, using different ports on the GPU, using only the problematic monitor, but no matter what unless I turn off Force Composition Pipeline (Which I want so I can get rid of the tearing), the desktop would render at 30fps on the LG and sometimes 45 if I resized a window. Additional information such as the software versions I’m running will be down below.
My Hardware:
Intel Core i9 7980XE
128 GB of DDR4 3800 Mhz RAM
Gigabyte X299 Designare Ex
NVIDIA GeForce RTX 2080
LG 32UK50T (Primary), Acer XB280HK (Secondary)
Software:
Fedora 29 with KDE Plasma
KDE Plasma Version: 5.14.5
KDE Frameworks Version: 5.55.0
Qt Version: 5.11.3
Kernel Version: 5.0.9-200.fc29.x86_64
OS Type: 64-bit
NVIDIA Driver Version: 418.56
XOrg Config:
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 418.56
Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
EndSection
Section "Files"
EndSection
Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection
Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection
Section "Monitor"
# HorizSync source: edid, VertRefresh source: edid
Identifier "Monitor0"
VendorName "Unknown"
ModelName "LG Electronics LG Ultra HD"
HorizSync 30.0 - 135.0
VertRefresh 56.0 - 61.0
Option "DPMS"
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce RTX 2080"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-5"
Option "metamodes" "DP-4: 3840x2160_60 +0+0 {ForceCompositionPipeline=On}, DP-0: nvidia-auto-select +3840+0 {ForceCompositionPipeline=On}"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
Xrandr output:
Screen 0: minimum 8 x 8, current 7680 x 2160, maximum 32767 x 32767
DP-0 connected 3840x2160+3840+0 (normal left inverted right x axis y axis) 62
1mm x 341mm
3840x2160 60.00*+ 24.00
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)
DP-4 connected primary 3840x2160+0+0 (normal left inverted right x axis y axi
s) 600mm x 340mm
3840x2160 60.00*+ 30.00
2560x1440 59.95
1920x1080 60.00 59.94
1600x900 60.00
1280x1024 60.02
1280x800 59.81
1280x720 60.00 59.94
1152x864 59.96
1024x768 60.00
800x600 60.32
720x480 59.94
640x480 59.94 59.93
DP-5 disconnected (normal left inverted right x axis y axis)
USB-C-0 disconnected (normal left inverted right x axis y axis)