Changing screen resolution in CentOS

I'm trying to change my screen resolution to 1920x1200 with no luck. I actually did successfully change it, but once I log in it changes back to 800x600

3 Answers

The following has worked for me. Try running this on the command line:

First, make a backup of the config file:

cp /etc/X11/xorg.conf /etc/x11/backup.xorg.conf

Then configure the display to the resolution you want:

system-config-display --reconfig --set-resolution=1920x1200

You then have to restart X with ctrl-alt-backspace. I don't know of anyway to restart it on the command line but there could be a way. When I did this for the first time, I didn't restart X, and was mystified at why the resolution wasn't changing.

For my CentOS 7.2 I wanted to have 2560x1440 resolution to fit my iMac monitor First I executed

$ sudo xrandr
Screen 0: minimum 32 x 32, current 1920 x 1200, maximum 32768 x 32768
VNC-0 connected primary 1920x1200+0+0 0mm x 0mm 1024x768 60.00 1920x1200 60.00* 1920x1080 60.00 1600x1200 60.00 1680x1050 60.00 1400x1050 60.00 1360x768 60.00 1280x1024 60.00 1280x960 60.00 1280x800 60.00 1280x720 60.00 800x600 60.00 640x480 60.00 

Since max is 32768x32768 we can definitely do 2560x1440 resolution! First, added the new resolution mode:

$ sudo xrandr --newmode "2560x1440_60.00" 312.25 2560 2752 3024 3488 1440 1443 1448 1493 -hsync +vsync

Then added that mode to my VNC-0 screen

$ sudo xrandr --addmode VNC-0 "2560x1440_60.00"

Then, Under:

Applications Menu =>System Tools =>Settings =>Hardware:Dispays =>Unknown Display (Double click) =>Resolution =>2560x1440

You do not even need to restart GNU Desktop :)

before sudo xrandr --newmode you must do this

gtf 2560 1440 60 -x then use the command sudo xrandr --newmode and pick up the numbers from the gtf

or simply see