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My eyes hurt so I thought I should check the screen refresh rate (monitor frequency), but I couldn't find it.

Where is it? (in Ubuntu 12)

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  • 1
    If your eyes hurt, I suggest you check out the topic of color temperature correction (F.lux and redshift are two great apps for this)
    – Bernát
    Commented Jun 10, 2015 at 19:02
  • For me Unity seems to be the problem. I have an HDMI Y connector (two inputs, one output, you can choose which one to pass through), which I confirmed by a few tests: 1) I plugged another computer with the same driver/OS into the same thing and it flickered. 2) I lowered the resolution and it reduced the flicker but didn't remove it 3) I plugged my computer into the same thing with a USB-C to HDMI cable and it continued flickering 4) I plugged my computer directly with the USB-C to HDMI cable into the monitor and it continued flickering, although slightly reduced. 5) Mirroring doesn't flicker.
    – Lampe2020
    Commented Oct 8, 2023 at 20:09

2 Answers 2

Reset to default
81

Compiz looked like it worked. But it didn't work.

So the solution to this is the following.

First we check available modes.
$ xrandr
1440x900       59.9+*   75.0
1280x1024      75.0     60.0

Then we pick the mode, including resolution and refresh rate.
$ xrandr -s 1440x900 -r 75

Or just the refresh rate
$ xrandr -r 75

Let's see if it worked
$ xrandr
1440x900       59.9+    75.0*
1280x1024      75.0     60.0

Alright. Then all you have to do is add the command to Startup Applications and be done.

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    I wonder why didnt some one mention this ?????? Rate 75.0 Hz not available for this size" . Its not the correct solution at all.
    – Pratik Joshi
    Commented Feb 13, 2015 at 18:21
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    @PratikCJoshi Try using a different type of cable, for example HDMI.
    – Niel de Wet
    Commented Apr 13, 2016 at 13:30
  • @PratikCJoshi You probably used xrandr -r 75.0, which may not work, while xrand -r 75 should. Even if the displayed framerate is something like 74.98 (my case) you should take the nominal value and use xrandr -r 75.
    – fsanches
    Commented Oct 20, 2016 at 2:14
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    BTW, from here: star (*) is the current mode, the plus (+) is the preferred one. Most monitors report a preferred mode to the driver.
    – Pablo Bianchi
    Commented Apr 30, 2017 at 22:19
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    I recently needed to use the xrandr command as follows: xrandr --output eDP-1 --mode 1920x1080 --rate 59.93 for this to work, otherwise there was no change. Check the output device from the 2nd line of xrandr output. Would be nice if there was a way without adjusting xorg.conf or adding a startup script to make this permanent. Somehow 60.01 (= the default rate) makes my eyes bleed (screen flickers in the dark areas), whilst using 59.93 doesn't (recent HP Probook).
    – 4levels
    Commented Jun 22, 2018 at 23:59
16

open your terminal and type this 

sudo apt-get install compizconfig-settings-manager

then type compiz in your unity dash , it will list you compiz settings manager .Open compiz and at general options click at composite and there you have untick the detect refresh rate then you can manually set the value you want . enter image description here .

and two know allowed refresh rates for the resolution you can use xrandr

the second row are allowed refresh rates with respect to the resolutions . so by depending on resolutions you have set , you can change the refresh rate by using the above methods . enter image description here

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    How can I know which is the max allowed? Can't this break my monitor?
    – HappyDeveloper
    Commented Jun 7, 2012 at 3:08
  • Do you really think its that simple ??? It adjusts to 60Hz on reboot no matter what value you set !!!
    – Pratik Joshi
    Commented Feb 13, 2015 at 18:20
  • WARNING: Starting compiz broke my system and forced me to reboot
    – pubkey
    Commented May 9, 2020 at 12:00

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