adding display modes in Linux

Following various posts, first we use cvt to find a mode supported by the monitor and get the modeline, and then add it and enable it using xrandr:

cvt 1600 900

# this would return the relevant mode-line, which is copy-pasted below.

xrandr --newmode "1600x900_60.00"  118.25  1600 1696 1856 2112  900 903 908 934 -hsync +vsync

xrandr 

# use xrandr without arguments to find the display name, which was VGA-1 in this case

xrandr --addmode VGA-1 "1600x900_60.00"

If there is a working mode in Windows, we can use Powerstrip to find it, copy-paste the modeline and use it in Linux.

There are various ways to make this permanent, including xorg.conf editing as mentioned at

https://forums.linuxmint.com/viewtopic.php?t=271122

https://wiki.archlinux.org/title/Xorg#Using_xorg.conf

https://askubuntu.com/questions/63681/how-can-i-make-xrandr-customization-permanent

but the easiest way may be to make a script with the relevant commands and add it to ~/.xprofile

https://forums.linuxmint.com/viewtopic.php?t=274540