External monitor on Linux
1. 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
2. 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.
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.
Problems with autorandr
I now had two different laptops where autorandr caused problems. After connecting to a screen I had no output (not even on the laptop screen) and xrandr commands were "ignored": It returned immediately, but didn't change anything.
I don't know a good alternative, so I will keep custom xrandr scripts for my different displays. :(
I might try xlayoutdisplay in future, although it works a bit differently.
Update: This doesn't seem to be a problem of autorandr, but rather some display driver issue, even though I've experienced this issue on two different devices. I had the same problem with autorandr uninstalled and using xrandr directly now.