Changing refresh rate for specific monitor
Method 1
With the following command
xrandr --output HDMI1 --rate 75
Where the string after --output
is the name of the monitor and the number after --rate
is the new refresh rate
Or, if you want to make sure the resolution is correct too in the same command
xrandr --output HDMI1 --mode 1280x1024 --rate 75
See man xrandr
and the following link to learn more
https://wiki.ubuntu.com/X/Config/Resolution
Method 2
You should have a file monitors.xml (~/.config/monitors.xml)
Edit the file with your favorite text editor
vim ~/.config/monitors.xml
You will see monitors available, and you should recognize them by name.
Here's some example information you will see about a monitor
<vendor>AUO</vendor>
<product>0x38ed</product>
<serial>0x00000000</serial>
<width>1920</width>
<height>1080</height>
<rate>60</rate>
<x>0</x>
<y>0</y>
<rotation>normal</rotation>
<reflect_x>no</reflect_x>
<reflect_y>no</reflect_y>
<primary>yes</primary>
There's the line
<rate>60</rate>
Replace the current refresh rate with a new one. For example
<rate>75</rate>
Save the file and reboot, and the new refresh rate will take place.
NOTE: Make sure that monitor's resolution supports the refresh rate you are going to change