Managing displays in software

[WilliamKC]

I am running OpenBox on the i386 Ubuntu-mini-remix with kernel 3.8 and I am hoping someone can help me with dual monitor support in the absence of ubuntu-system-settings. I'll give you the long story in case it helps. My video card is a GeForce GT 610. Upon initial installation, both of my screens are mirrored, after I install the latest video driver, the screens are spanned. This means that the panel stretches from screen edge to screen edge. Also, if I try to center a wallpaper, it is split down the middle of the screen. nvidia-settings is rather useless in this scenario, and while Xinerama works like a charm, it unfortunately disables compositing, which is is a must.

I tried these commands:

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xrandr --output DVI-I-0 --offObviously that screen deactivates. So I then re-enable it with:

Code: [Sélectionner]

xrandr --output DVI-I-0 --auto --left-of DVI-I-3
This does not help achieve any real multiple monitor support. Below I am including my full xrandr output. I am starting to wonder if this is possible to manager without a utility such as what is found in ubuntu system-settings and am open to the idea of installing it. I tried once before but attempting to use the display configuration resulted in a rather dramatic error. Also, despite this being my output, I will need this functionality on different setups.

Thanks,

william

Screen 0: minimum 8 x 8, current 3280 x 1050, maximum 16384 x 16384
DVI-I-0 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 297mm
   1680x1050      60.0*+
   1440x900       75.0     59.9
   1280x1024      75.0     60.0
   1280x960       60.0
   1152x864       75.0
   1024x768       75.0     70.1     60.0
   800x600        75.0     72.2     60.3     56.2
   640x480        75.0     72.8     59.9
DVI-I-1 disconnected (normal left inverted right x axis y axis)
DVI-I-2 disconnected (normal left inverted right x axis y axis)
DVI-I-3 connected 1600x900+1680+0 (normal left inverted right x axis y axis) 432mm x 240mm
   1600x900       60.0*+
   1280x800       59.8
   1280x720       60.0
   1152x864       75.0
   1024x768       75.0     70.1     60.0
   800x600        75.0     72.2     60.3     56.2
   640x480        75.0     72.8     59.9

[melodie]

Hi William,

I see "screen 0" : where is the "screen 1" output from xrandr?

I will try to do some tests with a Bento on two different screens next week. I could suggest some command lines to add to your ~/.config/openbox/autostart file, for this I would need to know which screen is at the left of the other, and your preferred resolution for each of them.

For two screens which I had put in dual screen once, I used:

Code: [Sélectionner]

xrandr --auto --output VGA1 --mode 1280x1024 --left-of LVDS1 &
or

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xrandr --output VGA1 --mode 1680x1050 --left-of LVDS1
VGA1 is the naming of one of them, provided by xrandr, and LVDS1 the other (this one is the screen of a laptop, while VGA1 is an external screen).

VGA1 has one value in the above command lines, then another value : the reason is that it refers in fact to two different external monitors which I may have used at different times. (Both being seen by xrandr as "VGA1").

[WilliamKC]

Oops. It would help to past the entire output - not sure how that happened. I will take the information you provided and give it another try. I suppose I was hoping there might be a more end user friendly way to go about this.

[melodie]

Hi,

You could try the gui program arandr. I am not sure how better it is though.

From your output, it looks like the system sees your monitors as if they were one and only monitor. Is that one tower, with a GPU having two entries, one for each monitor?

How is it setup exactly?

PS: I just found this script, which you could try:

Code: [Sélectionner]

#! /bin/bash
# auto_ecran
# your_user@your_host


position="right-of"    # right-of left-of above below
cmd=""

for i in $(xrandr -q | grep " connected" | cut -d\  -f 1)
do
    ligne=$(xrandr -q | grep $i -n | cut -d: -f 1)
    res=$(xrandr -q | head -n $[$ligne+1] | tail -n 1 | awk '{ print $1}')
    if ! test -z $(echo $cmd | cut -d\  -f 1)
    then
        cmd=$cmd" --"$position" "$i
    fi
    cmd=$cmd" --output "$i" --mode "$res
done

for i in $(xrandr -q | grep " disconnected" | cut -d\  -f 1)
do
    cmd=$cmd" --output "$i" --off"
done

echo "xrandr"$cmd    #***

if ! xrandr $cmd
then
    exit 2
fi
exit 0

From here:
http://crunchbanglinux-fr.org/forum/viewtopic.php?id=834

It is started from the ~/.config/openbox/autostart file.

You could also visit this post:
https://bbs.archlinux.org/viewtopic.php?pid=789771#p789771

PS2: this one is interesting:
http://crunchbang.org/forums/viewtopic.php?id=6040

Thinking of this, might match your issue?

Problem solved.  I had the secondary monitor set as a separate X display, found that I needed to use Nvidia TwinView

[WilliamKC]

It does show both displays, somehow I managed to cut off some one it, Screen 0 is the cumulative resolution of both monitors:

Screen 0: minimum 8 x 8, current 3280 x 1050, maximum 16384 x 16384
DVI-I-0 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 297mm
   1680x1050      60.0*+
   1440x900       75.0     59.9 
   1280x1024      75.0     60.0 
   1280x960       60.0 
   1152x864       75.0 
   1024x768       75.0     70.1     60.0 
   800x600        75.0     72.2     60.3     56.2 
   640x480        75.0     72.8     59.9 
DVI-I-1 disconnected (normal left inverted right x axis y axis)
DVI-I-2 disconnected (normal left inverted right x axis y axis)
DVI-I-3 connected 1600x900+1680+0 (normal left inverted right x axis y axis) 432mm x 240mm
   1600x900       60.0*+
   1280x800       59.8 
   1280x720       60.0 
   1152x864       75.0 
   1024x768       75.0     70.1     60.0 
   800x600        75.0     72.2     60.3     56.2 
   640x480        75.0     72.8     59.9 
HDMI-0 disconnected (normal left inverted right x axis y axis)

I will try some of those things tomorrow, including twinview (felt burned after Xinerama). My big concern is how this issue might effect everyday end users.

[melodie]

Hi,

Then type

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$ xrandr > xrandr.txt
(without the $ of course)

and from there copy/paste the content of the xrandr.txt produced. It will help figure it out better than with a cumulative output (confusing outputs can't help getting a clear view on the situation).

The end users don't use dual screens, they don't know it is possible (and they have too much to learn for their basic use, generally. When they don't anymore, they aren't end users anymore, and they seek for answers on the web as most people do).