Ubuntu – How to change the monitor’s refresh rate


How do I change the monitor's refresh rate in Oneiric?

There is no option to do it in the Displays dialog now. By default it's 60Hz, but I need 75Hz on my monitor.

In previous releases there used to be such an option in the Displays dialog.

Edit – Half baked solution

The best I could do so far was:

xrandr -s 1280x1024 -r 75

This is perfect, but my problem is that it isn't permanent. It defaults back to 60 Hz after logging out and back in.

Perhaps this should go into some script and added to startup? I just don't know how to do that.

Best Answer

  • You should be able to use xrandr. Calculate the needed modelines for your resolution and refresh rate:

    cvt 1600 900 75

    (Here my example resolution is 1600x900.) Now create a new mode with xrandr:

    xrandr --newmode "1600x900_75.00" 104.00 1600 -hsync +vsync

    Add the new mode to xrandr:

    xrandr --verbose --addmode VGA-0 "1600x900_75.00"

    and activate it

    xrandr --output VGA-0 --mode "1600x900_75.00"

    Note that your values will be different. In particular, your monitor might not be VGA. Run the xrandr command with no arguments to find out the name of your monitor and use that instead. Running xrandr -q will display a list of available outputs.

    Here's some more information on xrandr.

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