Chaging refresher rate: solution.

Problem: My monitor allows to use 100 Hz at a resolution of 1024x768. But KRandRTray did not show this option, the highest selectable rate was 85 Hz. Although this should be flickerfree, there was nevertheless a slight flickering. I searched the web and found some possible solutions. The following instruction is supposed to work with

openSUSE 11.0
KDE 4.0

:stuck_out_tongue: Warning: If you try this, you do it on your own risk. Check screen handbooks and find out which refresher rates are allowed before trying.

:eek: Some visited websites told me, that using wrong refresher rates may cause damage to your monitor!

Possible solution:

Open terminal and enter

xmode -x 1024 -y 768 -r 100

You will get the corresponding modeline:

Modeline "1024x768" 113.31 1024 1096 1208 1392 768 769 772 814

Copy the last line and open


Look for

Section “Modes”

and paste the modeline into a new line right before the end of the section. If a modeline identified by “1024x768” already exists, replace it. Go to section “Screen”, find the right color depth and add “1024x768” to Subsection “Display”, line “Modes”. If the entry already exists, do nothing. Save file and reboot.

Of course you can adapt this method for other resolutions and refresher rates.

:confused: I think, I found a similar instruction within openSUSE online help, but unfortunately I did not bookmark it and did not find it again.

:eek: Please post a reply if there is something wrong or dangerous with this method. However it worked fine with my system.

Nothing wrong with this, the xmode command simply calculates the modeline required for the resolution/refresh rate - modern displays do not allow switching to resolutions that they do not support so they cannot be damaged this way anymore, you’ll simply get a “Out of range” message.