issues with xfce and X

mvaterlaus · Posted: Tue Jun 12, 2012 1:45 pm Post subject: issues with xfce and X

hi,
I now have installed xfce on my computer at work. everthing works fine, I have 2 displays of the same manufacturer and model. therefore i have configured two separate x screens, one for every display.

the clue now is, that i have the xfce panels only on the left display (which is screen 0), but i want it on both. does any one knows how this works? i searched the net but didn't found a solution when working with two separate x screens. any tips or search keywords are really appreciated.

the second issue I have, is that the displays have different resolutions and I don't know why. I do not have configured any settings for even one of the displays. Screen 0 has the dimensions 1920x1080 pixels (530x301 millimeters) and a resolution of 92x91 dots per inch. Screen 1 has the dimensions 1920x1080 pixels (650x366 millimeters) and a resolution of 75x75 dots per inch. Is there any way to change these values so both of the displays work with the same dimensions and resolutions?

Displays: Benq BL2400 (both)
Videocard: nVidia GeForce 8500 GT

[edit]
oops, i forgot to supply some more infos:
one of the monitors is connected at the dvi and the other on the vga port of the graphic card.
nvidia-drivers: 295.40
xorg-server: 1.11.4-r1
xfce-meta: 4.10
system: amd64 kernel 3.2.12
[/edit]

wcg · Guru Joined: 06 Jan 2009 Posts: 569

8500 GT is only the chip, the graphics processor, or gpu. Who made the card
(or the motherboard if the 8500 GT is embedded on the motherboard)?
The manual from the manufacturer may be available.

Chatter on the www says dual monitors with one on dvi and the other on vga
should work, but this could vary with the card, with the motherboard, etc,
which is why having the manual would be good. (Some cards expect you to
split the one dvi output with a dvi splitter cable to use dual monitors, while
others can use both the dvi output and vga output at the same time.)

If you have a graphics controller that can drive only the dvi port *or* the vga
port, but not both at the same time, that would explain why you only have
an image on one dispay, irrespective of how software tries to direct the output.
(There are plenty of possible software reasons why only one output port
is in use, but this can be an artifact of hardware limitations, too.)
_________________
TIA

mvaterlaus · Posted: Mon Jun 18, 2012 9:58 am Post subject:

thanks for the reply.
at the moment, both monitors do work. the problem is, that they do not have the same resolutions. the following resolutions are autoconfigured by xorg:

screen 0: dimensions 1920x1080 pixels (530x301 millimeters) and a resolution of 92x91 dpi
screen 1: dimensions 1920x1080 pixels (650x366 millimeters) and a resolution of 75x75 dpi

now what i want to accomplish is, that both of the screens have the same dimensions (in millimeters) and resolution. how do i configure that? for completition, the lspci output for my video card:

mvaterlaus · Posted: Mon Jun 18, 2012 12:37 pm Post subject:

update:
I fixed the problem with the different resolutions. I made the some changes in /usr/share/X11/xorg.conf.d/40-monitors.conf. I added the DisplaySize and Option "DPI" values to the config.

wcg · Guru Joined: 06 Jan 2009 Posts: 569

The Gentoo dual monitor guide has some guidance:
http://en.gentoo-wiki.com/wiki/X.Org/Dual_Monitors
_________________
TIA

mvaterlaus · Posted: Thu Jun 21, 2012 2:20 pm Post subject:

thanks for the reply,
I allready knew this guide, but it didn't helped me. I'm using the generated xorg config from the nvidia-settings tool. it launches two separate x-servers, but on the second screen there is still no panel. I don't know, how to go further from here, so other advices would be great.

Gusar · Posted: Thu Jun 21, 2012 2:57 pm Post subject:

Did you start a panel on the second screen? With separate screens you need to explicitly tell each app where it should start by using the DISPLAY variable.

derk · Posted: Thu Jun 21, 2012 6:17 pm Post subject:

try emerging and using arandr (a gui for xrandr) .. it will help you manage your screens (it installs under the settings menu in xfce)

Gusar · Posted: Thu Jun 21, 2012 6:53 pm Post subject:

arandr doesn't work with nvidia. Maybe with the 302.17 driver, but definitely not with pre-3xx drivers. Also, he's using separate screens, while xrandr and twinview used a merged framebuffer.

mvaterlaus · Posted: Mon Jun 25, 2012 7:49 am Post subject:

@Gusar: if I get you right, I should do something like the "code" below in my .xinitrc