Desktop still drawing for two monitors after one is gone

[DiscoStu570]

Here's the skinny. I had a dual monitor setup going for a while, then one monitor broke, and I dropped back down to one. In some ways, the computer seems to have noticed this. I have an NVIDIA card and the NVIDIA drivers, and in NVIDIA X Server Settings it shows only one display. I had it configured in the Xinerama fashion, two continuous desktops side by side.

However, my desktop is still drawn as though there are two monitors, the result being that I can only see half. This is easily apparent when I zoom out to the desktop cube. It wouldn't be much of a serious problem, except for some reason, several important applications I use for work are popping up messages on the part of the desktop that I can't access.

I installed the latest NVIDIA drivers, hoping a driver reset might prompt whatever the problem is to go away (and it's good to do that regularly anyways) but no dice. Anybody know what I need to modify to fix this?

[DiscoStu570]

Just gonna give myself a little bumparino here. I'm pretty sure this isn't an overly difficult problem to solve, anybody got a clue?

[uriel1998]

Hm. What does xrandr say for output? (I'm supposing that you've already run xrandr --auto with no luck, is that right?)

[DiscoStu570]

xrandr --auto appeared to do nothing.

The output of xrandr:
Screen 0: minimum 320 x 175, current 3200 x 1080, maximum 3200 x 1080
default connected 3200x1080+0+0 0mm x 0mm
3200x1080 50.0*
1920x1080 51.0
1680x1050 52.0 53.0
1600x1024 54.0
1440x900 55.0
1400x1050 56.0 57.0 58.0
1360x768 59.0 60.0
1280x1024 61.0 62.0 63.0
1280x960 64.0 65.0
1280x720 66.0
1152x864 67.0 68.0 69.0 70.0 71.0 72.0 73.0
1024x768 74.0 75.0 76.0 77.0 78.0 79.0
960x720 80.0 81.0
960x600 82.0
960x540 83.0
928x696 84.0 85.0
896x672 86.0 87.0
840x525 88.0 89.0 90.0 91.0 92.0
832x624 93.0
800x600 94.0 95.0 96.0 97.0 98.0 99.0 100.0 101.0 102.0 103.0
800x512 104.0
720x450 105.0
720x400 106.0
700x525 107.0 108.0 109.0 110.0
680x384 111.0 112.0
640x512 113.0 114.0 115.0
640x480 116.0 117.0 118.0 119.0 120.0 121.0 122.0 123.0
640x400 124.0
640x350 125.0
576x432 126.0 127.0 128.0 129.0 130.0 131.0 132.0
512x384 133.0 134.0 135.0 136.0 137.0
416x312 138.0
400x300 139.0 140.0 141.0 142.0 143.0
360x200 144.0
320x240 145.0 146.0 147.0 148.0
320x200 149.0
320x175 150.0

[uriel1998]

The output of xrandr:
Screen 0: minimum 320 x 175, current 3200 x 1080, maximum 3200 x 1080
default connected 3200x1080+0+0 0mm x 0mm
3200x1080 50.0*


Unless you have a 3200x1080 pixel monitor, this is your problem. For contrast, a VGA monitor I have hooked up right now:



Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192
VGA1 connected 1280x1024+1280+0 (normal left inverted right x axis y axis) 338mm x 270mm
1280x1024 60.0*+ 75.0
1152x864 75.0
1024x768 75.1 60.0
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1


(Getting pedantic for a moment in case others find this who need it.) The output of xrandr tells you a few things:

Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192

This is the size of your "desktop" when in a multi-monitor environment. I've got two monitors (each 1280 px wide) sitting side by side, so, 'natch, the X width of our desktop (across both monitors) is 2560. 1024 is the height. I could keep adding monitors (or resolution) until I hit 8192x8192.


VGA1 connected 1280x1024+1280+0 (normal left inverted right x axis y axis) 338mm x 270mm

This is my external monitor. It's only 1280x1024, which is as it should be.

So for yours, it really thinks your monitor is 3200x1080, and is drawing the desktop to that size. To hack it, try the following command (probably after reading this page on xrandr (http://web.archive.org/web/20080615222159/http://www.thinkwiki.org/wiki/Xorg_RandR_1.2) - it's one from the Wayback machine, but this is where I learned from - some of the things they say about Ubuntu are dated.):



xrandr --output default --mode 1280x800


PLEASE CHANGE THE RESOLUTION (1280x800) TO YOUR MONITOR'S RESOLUTION. And that's a lower-case "x" there as well....

Hope that helps!

[DiscoStu570]

Ah, yea that works. it looks a tad fuzzy atm (1280x800 didn't work at all , said xrandr: cannot find mode 1280x800) but 1600x1024 cut it down to the right size. I'll keep monkeying with it and find a resolution that looks right. I knew it was drawing it for two monitors, and I knew there was some terminal command to change it, because there always is, just didn't know what it was. Thanks for the assist :)

edit:1920x1080 looks perfect. Not that that information is of any use to anybody else. Just pumped from that 'I just fixed my computer's dumb problem' high.

[uriel1998]

Ah, yea that works. it looks a tad fuzzy atm (1280x800 didn't work at all , said xrandr: cannot find mode 1280x800) but 1600x1024 cut it down to the right size.
edit:1920x1080 looks perfect. Not that that information is of any use to anybody else. Just pumped from that 'I just fixed my computer's dumb problem' high.

Great! Glad to be of help - remember to mark the thread "solved"! ;)