How to find out, which screen is HEAD-0, HEAD-1, etc.?

If I want to use the name of my primary screen (HDMI-0, found out via xrandr) within another command, the device is never found.

Instead I have to use the name HEAD-0. From what I’ve already read I assume this is probably a nVidia-thing, but I don’t understand how it works, why it’s done and most importantly:

How can I find out, which of my screens has which HEAD-name?

Asked By: TheBeautifulOrc


Not sure if it’s the correct answer, but you can query connected displays via nvidia-settings --query dpys.

If I understand it correctly, HEAD-x is mapped to a display of the output of nvidia-settings in the order they appear. For example: HEAD-0 is the first connected display, HEAD-3 the fourth, etc.

Answered By: Alija

Command "nvidia-settings –query dpys" does not show HEAD-X names. Even "nvidia-settings -q all" does not.
Any chance to found them ?

Answered By: karpi