On each connect

Short command to set the correct resolution and scaling for an external monitor.
I’ve decided to write this down because the –scale-from parameter seems to be uncommon. Most suggestions on the internet only use –scale, which I find less intuitive to use.

# XPS 13 with full hd display
xrandr --output DP1 --primary --mode 1920x1080 --scale-from 1920x1080 --same-as eDP1
# XPS 15 with 4k display on an external WQHD display
xrandr --output DP1 --primary --mode 2560x1440 --scale-from 3840x2160 --same-as eDP1

Automate it by using autorandr

sudo pacman -S autorandr
sudo systemctl enable --now autorandr.service

I’ve created two profiles.

  • First, I connect no external monitor.
  • Then I run autorandr --save default.
  • Next, connect the external monitor.
  • Run the fitting xrandr command above. Check everything looks nice.
  • Run autorandr --save docked.

autorandr should switch to the correct mode automatically (hence the name) from now on.

What’s neat: If you close the lid while the notebook is connected to the external monitor, it doesn’t go into sleep mode.