Dell UP2414Q (UHD display) screen-halfs not synchronized


I have a Dell UP2414Q UHD display attached with DP cable to a GTX680, using driver 346.47 on ArchLinux (x86_64). Excerpt from the xorg.conf file:

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    # See
    Option "TwinView"
    Option "NoTwinViewXineramaInfo" "1"
    Option "metamodes" "DFP-4.9: 1920x2160 { ViewPortIn=1920x2160 }, DFP-4.8: 1920x2160 { ViewPortIn=1920x2160 }; DFP-4.9: 1920x2160 { ViewPortIn=1280x1440 }, DFP-4.8: 1920x2160 { ViewPortIn=1280x1440 }; DFP-4.9: 1920x2160 { ViewPortIn=960x1080 }, DFP-4.8: 1920x2160 { ViewPortIn=960x1080}; DFP-4.9: 1280x1440 { ViewPortIn=1280x1440 }, DFP-4.8: 1280x1440 { ViewPortIn=1280x1440 }; DFP-4.9: 960x1080 { ViewPortIn=960x1080 }, DFP-4.8: 960x1080 { ViewPortIn=960x1080}; DFP-4.9: 2560x1440 { ViewPortIn=2560x1440 }, NULL; DFP-4.9: 1920x1080 { ViewPortIn=1920x1080 }, NULL; DFP-4.9: 1920x1080_120 { ViewPortIn=1920x1080 }, NULL"
    Option "ConnectedMonitor" "DFP-4.9, DFP-4.8"
    Option "TwinViewOrientation"      "LeftOf"    
    SubSection     "Display"
        Depth       24

The screen mostly works fine in this setup. There used to be an issue that a screensaver-locked session would unlock with only one half of the screen working (the other staying black), but that seems to have disappeared with a recent driver update.

The one issue I still see is the fact that the left and right halfs of the screen are not synchronized correctly. This is most visible when scrolling a webpage in e.g. Firefox or moving a window vertically. There’s major screen-tearing in this case.

Is this due to the use of twinview? Any way to fix this?

nvidia-bug-report.log.gz (188 KB)

Okay, so the return-from-screensaver issue isn’t fixed. Just happened again that only half of the screen became active (left half). I noticed that the mouse cursor isn’t drawn, even though icons on the desktop do highlight when I hover them with the invisible cursor. Does that point to a driver/GPU issue?