1

Setup:

ThinkPad L450 [Ubuntu 16.04.5 LTS, kernel 4.13]: 1920 x 1080, Intel HD Graphics 5500 & UltraDock – 90W EU (DisplayPort 1.2)

ThinkPad L480 [Linux]: 1.920 x 1.080 (IPS), Intel UHD Graphics 620 & Lenovo ThinkPad Ultra Docking Station - 135 Watt (DisplayPort 1.4)

Benq PD2700U - 16:9, 3840 x 2160 4K UHD (2160p)

Dell U2518D - 16:9, QHD 2560 x 1440 at 60 Hz

  • both monitors can daisy chain

I can set up the monitors with daisy chain OR via the 2 DisplayPorts outputs of the Docking with a resolution of up to 2560 x 1440 (and 1920 x 1080 for the Laptop screen) for the L450 and L480 (with the docking stations).

BUT when I change the resolution of the Benq 4K monitor to 3840 x 2160 (59.xx Hz) it results in

  • ubuntu: dell 2k monitor gets black (but is shown to be still connected in xrandr --verbose | grep " connected")

Errors are:

could not set the configuration for CRTC 65

required virtual size does not fit available size: requested=(8320, 2160), minimum=(320, 200), maximum=(8192, 8192)

requested position/size for CRTC 65 is outside the allowed limit: position=(4480, 0), size=(3840, 2160), maximum=(8192, 8192)


The result of

xrandr --output DP-2-1-8 --mode 3840x2160 --rate 29.97 --primary --output DP-2-1-1 --mode 2560x1440 --rate 59.97 --right-of DP-2-1-8 --output eDP-1 --mode 1680x1050 --rate 59.95 --left-of DP-2-1-8

result of 2k 4k 1080p


It happens via the 2 DP ports and via daisy chain (Benq 4K to Dell 2K).

  • there was one sentence about NixOS and it had addition information value, but fine I hope now you can state your knowledge about the situation related to Ubuntu. – InLaw Feb 10 '19 at 15:15
  • Ubuntu kernel 4.13 is EOL & unsupported (has had no updates in a long time), so I'd suggest you upgrade your system. Ubuntu 16.04.5 should be using kernel 4.4 or 4.15. I don't know NIX OS, but are you running Ubuntu? – guiverc Feb 14 '19 at 4:20
0
pc="eDP-1"
benq="DP-2-1-8"  
dellb="DP-2-2"
xrandr -v --output ${benq}  --mode 3840x2160 --rate 29.97 --primary \
          --output ${dellb} --mode 2560x1440 --rate 59.95 --left-of  ${benq} \
          --output ${pc}    --mode 1600x900  --rate 59.99 --right-of ${benq} 

with a lower refresh rate and a smaller resolution of the laptop monitor is it working all right

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.