I know there are a million questions like this one, but I still feel this has it's own unique set of problems.
The main issue is: I want to run my external monitor in 4K resolution above 50Hz
xrandr clearly shows 3840x2160@50.00 Hz as an option (see output below) and it shows up as an option in every GUI, however - it just doesn't work.
X.org: As soon as I pick it the screen blanks out and reverts back to 4k@30Hz or 1440@60 Hz (whatever I was running before). Wayland: Wayland will claim it's running at 4K, but the DPI is to low. This means I only can see something like 1920x1080 pixels on my monitor and the remaining 3/4 of the desktop is displayed outside my monitor - making it impossible to use. I should be noted I have no interest in running wayland unless it makes my life easier :) I just provided the information here because I found it interesting.
One would think this could be due to a faulty cable, but my two other windows laptops I tried has managed to run 4K@60Hz (or 50Hz) just fine, so the bandwidth from the dock to the monitor seems to be high enough.
The hardware setup is as follows:
- laptop (with the issue): Thinkpad P43s
- Running Ubuntu 22.10 with version 525.89.02 of the nvidia drivers
- a dock: Lenovo ThinkPad USB-C Dock Gen2. Connected to the laptop using Thunderbolt 3
- a monitor: Dell s3221qs (connected with displayport 1.2)
I've also included the verbose output of me setting the resolution manually from the command line. 4K@30Hz works while 50Hz does not for some reason
If anyone have any good idea for what to try next - I would love to hear them.
Output from xrandr:
myuser@myuser-ThinkPad-P43s:~$ xrandr
Screen 0: minimum 320 x 200, current 4480 x 1440, maximum 16384 x 16384
eDP-1 connected 1920x1080+0+360 (normal left inverted right x axis y axis) 309mm x 173mm
1920x1080 60.00*+ 60.00
1680x1050 60.00
1400x1050 60.00
1600x900 60.00
1280x1024 60.00
1400x900 60.00
1280x960 60.00
1440x810 60.00
1368x768 60.00
1280x800 60.00
1280x720 60.00
1024x768 60.00
960x720 60.00
928x696 60.00
896x672 60.00
1024x576 60.00
960x600 60.00
960x540 60.00
800x600 60.00
840x525 60.00
864x486 60.00
700x525 60.00
800x450 60.00
640x512 60.00
700x450 60.00
640x480 60.00
720x405 60.00
684x384 60.00
640x360 60.00
512x384 60.00
512x288 60.00
480x270 60.00
400x300 60.00
432x243 60.00
320x240 60.00
360x202 60.00
320x180 60.00
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
DP-2-1 disconnected (normal left inverted right x axis y axis)
DP-2-2 disconnected (normal left inverted right x axis y axis)
DP-2-3 connected primary 2560x1440+1920+0 (normal left inverted right x axis y axis) 697mm x 392mm
3840x2160 50.00 30.00 25.00 24.00 29.97 23.98
2560x1440 59.95*
1920x1200 59.88
1920x1080 60.00 50.00 59.94
1600x1200 60.00
1680x1050 59.95
1600x900 60.00
1280x1024 75.02 60.02
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.03 60.00
800x600 75.00 60.32
720x576 50.00
720x480 60.00 59.94
640x480 75.00 60.00 59.94
720x400 70.08
Set resolution from command line
myuser@myuser-ThinkPad-P43s:~$ xrandr --output DP-2-3 --mode 3840x2160 --rate 50.00 --verbose
screen 0: 3840x2160 1016x571 mm 96.00dpi
crtc 0: 3840x2160 50.00 +0+0 "DP-2-3"
xrandr: Configure crtc 0 failed
crtc 0: disable
crtc 1: disable
crtc 2: disable
screen 0: revert
crtc 0: revert
crtc 1: revert
crtc 2: revert
myuser@myuser-ThinkPad-P43s:~$ xrandr --output DP-2-3 --mode 3840x2160 --rate 30.00 --verbose
screen 0: 3840x2160 1016x571 mm 96.00dpi
crtc 0: 3840x2160 30.00 +0+0 "DP-2-3"
myuser@myuser-ThinkPad-P43s:~$
