I bought a new 43" 4k monitor. Due the limitation of graphic card I had to manually add th resolution which I wanted. I am trying to sqeeue as many pixels as I can get for a decent refresh rate.

When I use the below values my computer works fine and the display is decent enough. However the desktop seems to get get duplicated on the monitor. I have attached the image to explain not sure why there is an overlap.enter image description here

  • cvt 2880 1575 35
  • sudo xrandr --newmode "2880x1575_35.00" 214.25 2880 3048 3344 3808 1575 1578 1588 1609 -hsync +vsync
  • sudo xrandr --addmode HDMI-1 2880x1575_35.00 -xrandr --verbose --output HDMI-1 --mode 2880x1575_35.00

Thank you,v

update Aug/13/2017

The below config works fine. If I increase the width pixel then it starts to duplicate. The more pixel I add the more the duplicate workspace show up.

  • cvt 2048 1152 60 // The refresh rate does not affect the issue.
  • sudo xrandr --newmode "2048x1152_60.00" 197.00 2048 2184 2400 2752 1152 1155 1160 1195 -hsync +vsync
  • sudo xrandr --addmode HDMI-1 2048x1152_60.00
  • xrandr --verbose --output HDMI-1 --mode 2048x1152_60.00

1 Answer 1


after adding mode you should run xrandr with both displays as parameters.

So after this xrandr --addmode HDMI-1 2880x1575_35.00 you should run xrandr --output eDP1 --mode 1920x1080 --output HDMI-1 --mode 2880x1575_35.00 --right-of eDP1

in this command I assume that your primary laptop display is eDP1 you can get them by running xrandr without parameters and that 1920x1080 is resolutio you want on laptop on other side for a 43" display you use new mode don't forget the last part of that --right-of eDP1 which instructs to place a display right of the eDP1.

  • I tried your suggestion but it did not work. The laptop display is workign fine the new 43" 4k still shows the desktop twice. Aug 12, 2017 at 18:10
  • It might be that you are using incorrect size of the mode. If you want 16x9 resolution then you need 1920/1080.0 * 1575 which equals 2800 not 2880. Also why so low refresh rate?
    – MarkoShiva
    Aug 12, 2017 at 18:16
  • sorry 2800 did not work. I am using a low refresh rate as my card can't take the load. It can only handle 200 pixel clocks. You can read more about it here medium.com/@ValdikSS/… Aug 12, 2017 at 18:27

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