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@wvengen /
Last active Jan 19, 2018

What would you like to do?
Extend non-HiDPI external display above HiDPI internal display
# extend non-HiDPI external display on DP* above HiDPI internal display eDP*
# see also
# you may run into
EXT=`xrandr --current | sed 's/^\(.*\) connected.*$/\1/p;d' | grep -v ^eDP | head -n 1`
INT=`xrandr --current | sed 's/^\(.*\) connected.*$/\1/p;d' | grep -v ^DP | head -n 1`
ext_w=`xrandr | sed 's/^'"${EXT}"' [^0-9]* \([0-9]\+\)x.*$/\1/p;d'`
ext_h=`xrandr | sed 's/^'"${EXT}"' [^0-9]* [0-9]\+x\([0-9]\+\).*$/\1/p;d'`
int_w=`xrandr | sed 's/^'"${INT}"' [^0-9]* \([0-9]\+\)x.*$/\1/p;d'`
off_w=`echo $(( ($int_w-$ext_w)/2 )) | sed 's/^-//'`
xrandr --output "${INT}" --auto --pos ${off_w}x${ext_h} --scale 1x1 --output "${EXT}" --auto --scale 2x2 --pos 0x0

How do you change this to be right of the main display? eDP1

@JherezTaylor add ``--right-of eDP1to the end of finalxrandr`

a123qwertz567 commented Nov 10, 2016

I came here by the ArchWiki article "HiDPI". Maybe you can help me...I came here to ask because I am not sure to which forum I should go. If I get a hint I will post at another place....

Your script isn't really working for me now but this (from the wiki) works for me:
xrandr --output eDP-1 --auto --output HDMI-1 --auto --panning 3840x2160+3840+0 --scale 2x2 --right-of eDP-1
BUT my hardware setup would need a --left-of. But with by replacing right with left I get a non-good result. I am not sure if it is a panning thing. Still not sire how this works. I think --left-of doesn't make a big difference.

EDIT: Specify "non-good": HiDPI screen fine all the time. LowDPI(FullHD) screen is broken. It is like the screen 4k in the "background". When I go over to the screen around the mouse it is like a zoom rectangle of the size 1920x1080 on the 4k "bachground"....This is difficult to discribe or so screenshot.... :(

raininja commented Jan 4, 2017

I also get a "bad" result on my Asus 1920x1080 device. . . I also require a "left of" configuration. . . looking at these sed scripts. . . I wonder if there is a cleaner method. . .

krizajb commented Nov 8, 2017

Same thing is happening to me as for @a123qwertz567. Did you guys figure something out?

luispabon commented Dec 7, 2017

This works well for my current set up where I have a 4K laptop (XPS 9560) beneath a FHD external display, but I have to run it twice: first time the external monitor has a big chunk of whatever's on the 4K monitor, and the second time it goes in fine.

On Unity, connect first the external monitor, and on display config make sure the scale factor for both screens is 2. Then run the script, perhaps twice.

The downside of this approach is however the FHD monitor is a scaled down version of 4K, so your computer is in fact driving 2x4K monitors (plus the overhead of resampling) and this is very resource intensive. The image quality on the FHD monitor is not great.

I see the same as above with gnome 3. Unfortunately sometimes it doesn't seem to actually work on the second run

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