Screen resolution

[Guest]

Hi all,

I have a problem with screen resolution. The maximum I have is 1024x768 and of course it's not enough.
I was able to use xrandr commands in terminal such as:
xrandr --newmode "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync
xrandr --addmode DVI-0 1368x768_60.00
xrandr --output DVI-0 --mode 1368x768_60.00

Resolution changes perfectly, but I have no idea, how to make it permanent. When I try to edit Xsetup through Alt + F2 "kdesudo kate /etc/kde4/kdm/Xsetup" gives me only error message: Check that you have write access to this file or that enough disk space is available.
It seems like that the file doesn't even exist and really don't know what to do next.

Thank you for your help.

[oshunluvr]

You don't say what release of Kubuntu you're using but in 15.04, sddm is the display manager not kdm. kdm hasn't been the default for several years and you don't have it on your system unless you installed it. If I remember correctly, Xsetup was in /etc/X11 back then, but you can easily search for it using locate.

[Shabakthanai]

Have you opened the driver manager to see if there is a more current driver for your GPU. Perhaps there are additional options available in a newer driver, if available. Just a thought.