After working with me for a day or two, KDE decided that my randr settings were not worth remembering.
I have a GTX 550ti card and am using twinview.
(The more 'native' option that just got support a month ago does not support composting yet, for some reason.).

What baffles me is that, the startup file of krandr records the original settings.

Code: Select all

[Display]
ApplyOnStartup=true
StartupCommands=xrandr --output VGA-0 --pos 1920x0 --mode 1366x768 --refresh 59.7895\nxrandr --output HDMI-0 --pos 0x0 --mode 1920x1080 --refresh 60\nxrandr --output HDMI-0 --primary

[Screen_0]
OutputsUnified=false
UnifiedRect=0,0,0,0
UnifiedRotation=1

[Screen_0_Output_HDMI-0]
Active=true
Rect=0,0,1920,1080
RefreshRate=60
Rotation=1

[Screen_0_Output_VGA-0]                                                                                                                                                                     
Active=true
Rect=1920,0,1366,768
RefreshRate=59.7895393371582
Rotation=1


(Telling krandrstartup or krandrtray to autostart at boot does not help..this was a suggested solution in some previous posts here.)

But manually running the following randr commands (derived from the above file itself !) does what is needed:

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xrandr --output VGA-0 --pos 1920x0 --mode 1366x768 --refresh 59.7895
xrandr --output HDMI-0 --pos 0x0 --mode 1920x1080 --refresh 60
xrandr --output HDMI-0 --primary


More strangely, putting the above 3 commands in a script and setting to start at boot makes KDE unusable and also does not execute the commands.
Any idea what might be wrong ?

Which method did you use to get those three commands to run?
I would recommend placing an executable script in ~/.config/autostart which should work. It may need to have a *.sh extension.

That is what I did.
Well, not exactly... I did it through "System Settings", but that is where the resulting script gets copied!
(And when executed from there crawls down all KDE specific programs and the desktop.)

Anyway, I found out the problem.
"nvidia-settings" was not saving its settings, because it didn't have the authorization to merge the changes into xorg's config files.

I *think* KDE's randr system ignores its own settings at startup when "nvidia-settings" is used.
Whether that is a bug or a design decision, I have no idea.