I purchased a new monitor which, unlike my old one, required manually setting up display settings in xorg.conf. KDE seems to ignore these settings in xorg.conf, as when I try to launch KDE I get the same test pattern on the monitor as I did before I had xorg.conf set up correctly. The users on the KDE forums were unable to help, but I've included the relevant thread in case anyone wants to look at it. Reproducible: Always Steps to Reproduce: 1. Attach QNIX monitor, which currently cannot get auto-configured by xorg 2. Manually set up monitor inside xorg.conf 3. Attempt to launch KDE Actual Results: KDE displays same test pattern as it did before xorg.conf had been manually configured. Expected Results: Displaying of the KDE Desktop. * Using KDM * Using Nvidia's closed-source driver, 331.79 * This bug occurs even for brand-new user accounts with no previous settings in .local, .kde, etc. * This still occurs after creating a brand-new user, so it seems unrelated
Might be related to Bug 317929 , but I could not tell for certain.
Correction to original description's "Actual Results": The test pattern is what the monitor would display when attempting to launch any X session at all before xorg.conf was manually configured. This included fluxbox and Gnome. So the test pattern seems to be what the monitor does when it's not receiving usuable... display modes? from X.
Update: I no longer believe this is the fault of KDE, but rather the properietary Nvidia drivers. From what I understand, the properietary Nvidia driver ignores the modes defined in the xorg.conf file unless you give a "IncludeImplicitMetaModes" "no" option to the driver in the /etc/X11/xorg.conf file. My understanding is that this happens when it uses OpenGL, so I assume fluxbox and Gnome were not hitting the same problem due to not using OpenGL rendering.
You could confirm by switching kwin to XRender mode; then it does not use OpenGL.
Marking as duplicate of bug 317929 - KScreen currently ignores xorg.conf and will try to set what it thinks is the best for you if there's no previous KScreen configuration for that specific monitor - if this is different from what you set in xorg.conf, it will lead to the effect you describe. So although technically it's probably monitor or GPU vendor's fault it's not handling "nonstandard" settings correctly, it's still more of KScreen's fault it does not honor your config. *** This bug has been marked as a duplicate of bug 317929 ***