Can't set the native resolution for an external VGA 1080p monitor with xrandr or settings
I have a fresh install of Ubuntu 20.04.1 LTS and I can't set the external 1920x1080p monitor connect by a VGA cable to its native resolution. By default on boot its set to 1024x768p and from settings I don't have a bigger option. Hardware: Intel i7 4710HQ, Intel HD 4600, Nvidia 840M (tried with 460 property and X.Org Nouveau drivers) What I tried: With xrandr I can set it to 1912x1080p and I works. For 1920x1080p, after I add the mode with xrandr, when I try to set it to that resolution in settings the monitor flashes black and gets back to the resolution set before it. Have any idea how to fix it so I can use the monitor's resolution? EDIT -> Monitor model: Dell SE2419HR Commands used:
cvt 1912 1080
xrandr --newmode "1912x1080_60.00" 171.25 1912 2032 2232 2552 1080 1083 1093 1120 -hsync +vsync
xrandr --addmode VGA-1-1 "1912x1080_60.00"
cvt 1920 1080
xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
xrandr --addmode VGA-1-1 "1920x1080_60.00"
You have not given a make/model of the monitor or said how you attempted to use xrandr to set the resolution so I would suggest you edit your question with those details.
You need to use cvt
to generate a "modeline" for example:
cvt 1920 1080
or with a refresh rate depending what your graphics/monitor can handle:
cvt 1920 1080 60
(Also, for some hardware you may have to use reduced timing mode: cvt -r 1920 1080
)
Then you need to pass the generated modeline to xrandr for example:
xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
Here is a good reference for xrandr