Dual monitor issues

Skaperen · 12-06-2009, 09:03 AM

I have a laptop with a 1920x1200 display, and a 24 inch desktop monitor that does 1920x1200 plugged into the VGA output of the laptop. There are some display configuration choices. But the only one that actually brings the big monitor alive (e.g. outputs video from the VGA port) is the "twin view" where the displays can be side by side.

I don't really want a side by side mode. That's because the laptop monitor is just impractical at the desk, and made worse because the only space to position it when at the desk sets it further back making its small monitor even harder to see. Many applications, such as the folder browser when I plug in external drives, pop up in the laptop display and I have to drag them over.

When I try to configure other modes (trying to see if they might give me what I want since the terminology doesn't really say), only the laptop display gets any video. The big monitor (e.g. the VGA port) doesn't get any in these modes.

What I want is for a display mode which is just 1920x1200 and displays on the big monitor.

If I can get two independent displays, each of which can select a virtual desktop separately, at the same time, that would be a plus. Even better if they can login, logout, and switch user separately. But I don't know if the video card can let me run two instances of X or not (Ubuntu seems to be doing background instances of X to manage switching users).

But even if it just gives me one 1920x1200 display and shows exactly the same thing on both displays all the time, that's more usable than what I have now.

Later when I move to a real desktop workstation with two real monitors then the 3840x1200 side by side mode would be fine.

Another issue is that when I try to save the configuration I do have, I get an error message popup that it is unable to parse the xorg.conf file. The file exists, appears to be a very simple stock configuration, and I would think it should be able to parse and modify that. So I have to manually set up this two display configuration every time I login.

The laptop is a Dell M4400. I don't know much else about it, yet.

janoszen · 12-06-2009, 03:48 PM

Please post the output of xrandr and optionally try to set your video modes with it. My dual head configuration works like this:

Code:

xrandr --newmode 1680x1050 146.25  1680 1784 1960 2240  1050 1053 1059 1089 -hsync +vsync
xrandr --addmode VGA1 1680x1050
xrandr --output LVDS1 --auto --mode 1280x800 --output VGA1 --auto --mode 1680x1050 --right-of LVDS1

jay73 · 12-06-2009, 04:48 PM

If you have an nvidia graphics chip, you may need to run sudo nvidia-xconfig first. I had the same parsing issue and it turned out that for whatever reason my xorg.conf was not properly configured until I ran the xconfig thingy.

Skaperen · 12-07-2009, 09:51 AM

Quote:

Originally Posted by janoszen

Please post the output of xrandr and optionally try to set your video modes with it. My dual head configuration works like this:

Code:

xrandr --newmode 1680x1050 146.25  1680 1784 1960 2240  1050 1053 1059 1089 -hsync +vsync
xrandr --addmode VGA1 1680x1050
xrandr --output LVDS1 --auto --mode 1280x800 --output VGA1 --auto --mode 1680x1050 --right-of LVDS1

Here is the output from xrandr:

Code:

Screen 0: minimum 320 x 240, current 3840 x 1200, maximum 3840 x 1200
default connected 3840x1200+0+0 0mm x 0mm
   1920x1200      50.0     51.0     84.0  
   1920x1080      52.0  
   1680x1050      53.0     54.0  
   1600x1024      55.0  
   1440x900       56.0  
   1400x1050      57.0  
   1360x768       58.0     59.0  
   1280x1024      60.0  
   1280x960       61.0  
   1152x864       62.0  
   1024x768       63.0  
   960x600        64.0  
   960x540        65.0  
   840x525        66.0     67.0  
   800x600        68.0     69.0     70.0  
   800x512        71.0  
   720x450        72.0  
   700x525        73.0  
   680x384        74.0     75.0  
   640x512        76.0  
   640x480        77.0     78.0  
   576x432        79.0  
   512x384        80.0  
   400x300        81.0     82.0  
   320x240        83.0  
   3840x1200      51.0*

Here is the output with --verbose option used:

Code:

Screen 0: minimum 320 x 240, current 3840 x 1200, maximum 3840 x 1200
default connected 3840x1200+0+0 (0x294) normal (normal) 0mm x 0mm
        Identifier: 0x262
        Timestamp:  202810
        Subpixel:   unknown
        Clones:    
        CRTC:       0
        CRTCs:      0
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter: 
  1920x1200 (0x263)  115.2MHz
        h: width  1920 start    0 end    0 total 1920 skew    0 clock   60.0KHz
        v: height 1200 start    0 end    0 total 1200           clock   50.0Hz
  1920x1200 (0x264)  117.5MHz
        h: width  1920 start    0 end    0 total 1920 skew    0 clock   61.2KHz
        v: height 1200 start    0 end    0 total 1200           clock   51.0Hz
  1920x1080 (0x265)  107.8MHz
        h: width  1920 start    0 end    0 total 1920 skew    0 clock   56.2KHz
        v: height 1080 start    0 end    0 total 1080           clock   52.0Hz
  1680x1050 (0x266)   93.5MHz
        h: width  1680 start    0 end    0 total 1680 skew    0 clock   55.7KHz
        v: height 1050 start    0 end    0 total 1050           clock   53.0Hz
  1680x1050 (0x267)   95.3MHz
        h: width  1680 start    0 end    0 total 1680 skew    0 clock   56.7KHz
        v: height 1050 start    0 end    0 total 1050           clock   54.0Hz
  1600x1024 (0x268)   90.1MHz
        h: width  1600 start    0 end    0 total 1600 skew    0 clock   56.3KHz
        v: height 1024 start    0 end    0 total 1024           clock   55.0Hz
  1440x900 (0x269)   72.6MHz
        h: width  1440 start    0 end    0 total 1440 skew    0 clock   50.4KHz
        v: height  900 start    0 end    0 total  900           clock   56.0Hz
  1400x1050 (0x26a)   83.8MHz
        h: width  1400 start    0 end    0 total 1400 skew    0 clock   59.8KHz
        v: height 1050 start    0 end    0 total 1050           clock   57.0Hz
  1360x768 (0x26b)   60.6MHz
        h: width  1360 start    0 end    0 total 1360 skew    0 clock   44.5KHz
        v: height  768 start    0 end    0 total  768           clock   58.0Hz
  1360x768 (0x26c)   61.6MHz
        h: width  1360 start    0 end    0 total 1360 skew    0 clock   45.3KHz
        v: height  768 start    0 end    0 total  768           clock   59.0Hz
  1280x1024 (0x26d)   78.6MHz
        h: width  1280 start    0 end    0 total 1280 skew    0 clock   61.4KHz
        v: height 1024 start    0 end    0 total 1024           clock   60.0Hz
  1280x960 (0x26e)   75.0MHz
        h: width  1280 start    0 end    0 total 1280 skew    0 clock   58.6KHz
        v: height  960 start    0 end    0 total  960           clock   61.0Hz
  1152x864 (0x26f)   61.7MHz
        h: width  1152 start    0 end    0 total 1152 skew    0 clock   53.6KHz
        v: height  864 start    0 end    0 total  864           clock   62.0Hz
  1024x768 (0x270)   49.5MHz
        h: width  1024 start    0 end    0 total 1024 skew    0 clock   48.4KHz
        v: height  768 start    0 end    0 total  768           clock   63.0Hz
  960x600 (0x271)   36.9MHz
        h: width   960 start    0 end    0 total  960 skew    0 clock   38.4KHz
        v: height  600 start    0 end    0 total  600           clock   64.0Hz
  960x540 (0x272)   33.7MHz
        h: width   960 start    0 end    0 total  960 skew    0 clock   35.1KHz
        v: height  540 start    0 end    0 total  540           clock   65.0Hz
  840x525 (0x273)   29.1MHz
        h: width   840 start    0 end    0 total  840 skew    0 clock   34.7KHz
        v: height  525 start    0 end    0 total  525           clock   66.0Hz
  840x525 (0x274)   29.5MHz
        h: width   840 start    0 end    0 total  840 skew    0 clock   35.2KHz
        v: height  525 start    0 end    0 total  525           clock   67.0Hz
  800x600 (0x275)   32.6MHz
        h: width   800 start    0 end    0 total  800 skew    0 clock   40.8KHz
        v: height  600 start    0 end    0 total  600           clock   68.0Hz
  800x600 (0x276)   33.1MHz
        h: width   800 start    0 end    0 total  800 skew    0 clock   41.4KHz
        v: height  600 start    0 end    0 total  600           clock   69.0Hz
  800x600 (0x277)   33.6MHz
        h: width   800 start    0 end    0 total  800 skew    0 clock   42.0KHz
        v: height  600 start    0 end    0 total  600           clock   70.0Hz
  800x512 (0x278)   29.1MHz
        h: width   800 start    0 end    0 total  800 skew    0 clock   36.4KHz
        v: height  512 start    0 end    0 total  512           clock   71.0Hz
  720x450 (0x279)   23.3MHz
        h: width   720 start    0 end    0 total  720 skew    0 clock   32.4KHz
        v: height  450 start    0 end    0 total  450           clock   72.0Hz
  700x525 (0x27a)   26.8MHz
        h: width   700 start    0 end    0 total  700 skew    0 clock   38.3KHz
        v: height  525 start    0 end    0 total  525           clock   73.0Hz
  680x384 (0x27b)   19.3MHz
        h: width   680 start    0 end    0 total  680 skew    0 clock   28.4KHz
        v: height  384 start    0 end    0 total  384           clock   74.0Hz
  680x384 (0x27c)   19.6MHz
        h: width   680 start    0 end    0 total  680 skew    0 clock   28.8KHz
        v: height  384 start    0 end    0 total  384           clock   75.0Hz
  640x512 (0x27d)   24.9MHz
        h: width   640 start    0 end    0 total  640 skew    0 clock   38.9KHz
        v: height  512 start    0 end    0 total  512           clock   76.0Hz
  640x480 (0x27e)   23.7MHz
        h: width   640 start    0 end    0 total  640 skew    0 clock   37.0KHz
        v: height  480 start    0 end    0 total  480           clock   77.0Hz
  640x480 (0x27f)   24.0MHz
        h: width   640 start    0 end    0 total  640 skew    0 clock   37.4KHz
        v: height  480 start    0 end    0 total  480           clock   78.0Hz
  576x432 (0x280)   19.7MHz
        h: width   576 start    0 end    0 total  576 skew    0 clock   34.1KHz
        v: height  432 start    0 end    0 total  432           clock   79.0Hz
  512x384 (0x281)   15.7MHz
        h: width   512 start    0 end    0 total  512 skew    0 clock   30.7KHz
        v: height  384 start    0 end    0 total  384           clock   80.0Hz
  400x300 (0x282)    9.7MHz
        h: width   400 start    0 end    0 total  400 skew    0 clock   24.3KHz
        v: height  300 start    0 end    0 total  300           clock   81.0Hz
  400x300 (0x283)    9.8MHz
        h: width   400 start    0 end    0 total  400 skew    0 clock   24.6KHz
        v: height  300 start    0 end    0 total  300           clock   82.0Hz
  320x240 (0x284)    6.4MHz
        h: width   320 start    0 end    0 total  320 skew    0 clock   19.9KHz
        v: height  240 start    0 end    0 total  240           clock   83.0Hz
  1920x1200 (0x292)  193.5MHz
        h: width  1920 start    0 end    0 total 1920 skew    0 clock  100.8KHz
        v: height 1200 start    0 end    0 total 1200           clock   84.0Hz
  3840x1200 (0x294)  235.0MHz *current
        h: width  3840 start    0 end    0 total 3840 skew    0 clock   61.2KHz
        v: height 1200 start    0 end    0 total 1200           clock   51.0Hz

I don't yet know what option to give to xrandr for what I want. I'll see if I can figure out something from your sample and the man page.

Skaperen · 12-07-2009, 10:47 AM

Quote:

Originally Posted by jay73

If you have an nvidia graphics chip, you may need to run sudo nvidia-xconfig first. I had the same parsing issue and it turned out that for whatever reason my xorg.conf was not properly configured until I ran the xconfig thingy.

I made a backup of /etc/X11 first then ran

Code:

nvidia-xconfig -o /root/nvidia-x.conf

which write BOTH /etc/X11/xorg.conf and /root/nvidia-x.conf but not exactly the same. The difference is:

Code:

--- /etc/X11/xorg.conf	2009-12-07 11:38:30.000000000 -0500
+++ /root/nvidia-x.conf	2009-12-07 11:39:52.000000000 -0500
@@ -1,9 +1,10 @@
 # nvidia-xconfig: X configuration file generated by nvidia-xconfig
 # nvidia-xconfig:  version 1.0  (buildmeister@builder58)  Fri Aug 14 18:33:37 PDT 2009
 
+
 Section "ServerLayout"
     Identifier     "Layout0"
-    Screen      0  "Screen0"
+    Screen      0  "Screen0" 0 0
     InputDevice    "Keyboard0" "CoreKeyboard"
     InputDevice    "Mouse0" "CorePointer"
 EndSection
@@ -12,6 +13,7 @@
 EndSection
 
 Section "InputDevice"
+
     # generated from default
     Identifier     "Mouse0"
     Driver         "mouse"
@@ -22,6 +24,7 @@
 EndSection
 
 Section "InputDevice"
+
     # generated from default
     Identifier     "Keyboard0"
     Driver         "kbd"

Notice the Screen statement is slightly different. Strange it wrote /etc/X11/xorg.conf despite -o telling it to write elsewhere (at least I made a backup before). But even more strange these files are different.

Skaperen · 12-07-2009, 12:00 PM

I ran nvidia-xconfig and let it rebuild the xorg.conf file (previously mentioned). Then I rebooted and logged into the userid I first set up (admin rights) and ran the Nvidia configuration there. I set up the twin-view across the two monitors.

When trying to save the configuration, it failed (claimed it could not create /etc/X11/xorg.conf.backup) due to permissions on the /etc/X11 directory. Apparently it doesn't run as root and doesn't go through whatever tool that prompts for password to do rootish things. So I "chmod 777 /etc/X11" temporarily and redid the configuration saving and that worked. They should update this to try to access root permission through whatever the other programs like package manager do it.

OK, so it seems to work. Reboot and login again and I get the twin display automatically by default. The next test failed: rebooting with the desk monitor turned off, having ONLY the laptop display. What I wanted is for it to detect there is no 2nd monitor, and fall back to 1920x1200 on the one display. The 3840x1200 mode across two monitors should only happen when two monitors are actually on (though I can see where in some cases people might want it to do it the other way, to avoid a restart of X just because one monitor was powered off). But in this case, if the laptop is being used portable, I really need it to be in a one monitor mode, particularly because the login prompt and the menu to restart/shutdown was on the other display screen (that had no working monitor). So my next chore is to figure out how to make it behave like that.