Hi,

I installed Fedora 11 on my laptop with Gnome first. Worked fine, dual monitor support not great, but works.

(I plug an LCD into the VGA port).

Now I've switched to KDE....

If I configure displays, I can see both monitors (the laptop's LCD monitor and the external VGA monitor).

I can enable, disable, change resolution, rotate etc. fine.

But, the only operation I can get is cloning - both monitors display the same stuff.

According to the Help documentation I should be able to select "Dual screen". The doco is from 2007, so it might be wrong.

I've searched these forums and elsewhere and some people talk about KDE4 with dual monitors working, and some say it isn't supported.

I've checked the online documentation.

What's the truth? Does KDE4 support dual monitors or not?

If not, will it?

BTW, what I want is increased work space either as a single desktop or as separate desktops. Can't see the point of cloning except for some teaching purpose.

TIA.

regards,
RR

If you enable Xinerama, MergedFB, etc then you can have support for multiple monitors. That is the only supported method currently.

But isn't Xinerama deprecated? And what does the Multiple Monitors section do...

Not sure about it being deprecated.... not sure what Multiple Monitors does, I've never used it. You may find KRandRTray to be of help.

http://sourceforge.net/projects/xinerama/

From the top of the page "As of 2007-09-20 00:00, this project is no longer under active development".

http://lists.freedesktop.org/archives/x ... 44394.html

"The "xinerama" implementation in the old XFree86 servers is
deprecated. So you shouldn't use that to configure your monitors.
Use xrandr instead."

So what to enable?

I'll give krandrtray a go. Surely the Multiple Monitors section should be tapping the same information as krandrtray?

So...

krandrtray. Looks great. Like the Multiple Monitors section in System Settings. As in similarly is missing completely anything that allows me to control how each monitor is placed in relation to another. Resolution, rotation (why?), refresh rate. All available in either System Settings or krandrtray.

Does anyone know where these settings have gone? Anyone know at all?

I think it may be a bug in the "Display" KCM module. This is the module that lists the monitors, shows their positioning, and has controls to resize, rotate, etc.

It has a "position" item as well, which is visible when a display is disconnected, but it doesn't show when a display is connected.

You may wish to try xrandr as a workaround, which has the switches to accomplish this.

Well, I remain confused. I have learnt this:

System Settings/Display module probably should be disabled as it doesn't do anything useful (at least with the ati/radeon driver); in fact it is less than useful, because having manually configured a rather beautiful (even though I say so myself ) dual screen setup, if you accidentally or deliberately enter the module it undoes all your work, overriding the settings made in xorg.conf or with xrandr. I remain unclear as to what it thinks it is doing to help...

For anyone coming across this who wants to emulate my (manual) success, here's my xorg.conf (relevant bits, commentary inbetween):

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Section "Device"
        Identifier      "Configured Video Device"
        Option "Monitor-DVI-1" "small"
        Option "Monitor-DVI-0" "wide"
EndSection


Mostly as default, except the Option lines - the first part is what the computer thinks your monitors/outputs are called, plus the "Monitor-", the second part is arbitrary and in my case descriptive. You can find out what your monitors are called by running

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xrandr -q

in Konsole e.g. my output is

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Screen 0: minimum 320 x 200, current 2720 x 1024, maximum 2720 x 1024
DVI-1 connected 1280x1024+1440+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      60.0*+   75.0     60.0*
   1152x864       75.0
   1024x768       75.0     70.1     60.0
   832x624        75.0
   800x600        72.2     75.0     60.3     56.2
   640x480        75.0     72.8     59.9
   720x400        70.1
DVI-0 connected 1440x900+0+0 (normal left inverted right x axis y axis) 410mm x 257mm
   1440x900       59.9*+
   1280x1024      75.0     60.0
   1440x900_59.90   59.9
   1280x960       60.0
   1152x864       75.0
   1024x768       75.0     70.1     60.0
   832x624        74.6
   800x600        72.2     75.0     60.3     56.2
   640x480        75.0     72.8     66.7     59.9
   720x400        70.1


You should clearly see the names above each monitor information section.

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Section "Monitor"
        Identifier      "small"
        Option "PreferredMode" "1280x1024_60"
        Option "RightOf" "wide"
EndSection


So here I have declared this one to the "small" monitor, told it my preferred mode (resolution and refresh rate) in the format widthxheight_refresh rate and said I would like it to be "RightOf" my "wide" monitor (just like it is on my desk).

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Section "Monitor"
        Identifier      "wide"
        Modeline "1440x900_59.90"  106.29  1440 1520 1672 1904  900 901 904 932  -HSync +Vsync
        Option "PreferredMode" "1440x900_59.90"
EndSection


So here I have declared this one as the "wide" monitor and told it my preferred mode - the modeline is left over from my experiments and may not be needed...

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Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        Device          "Configured Video Device"
 SubSection "Display"
        Depth           24
        # big virtual screen to place
        Virtual         2720 1024
    EndSubSection
EndSection


Here is mostly defaults except the SubSection "Display" where I am telling the computer I would like to be able to present a virtual display of a resolution up to 2720x1024, which is the width of my combined monitor's widths plus the height of the highest one, so to speak.

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Section "ServerFlags"
        Option  "DontZap"       "False"
EndSection


This is because actually Ctrl-Alt-Backspace to restart the graphical interface without restarting the PC as a while remains a useful feature and should be turned on. It should never have been disabled just because it is different to the expected behaviour in Windows for those keys. Linux ain't Windows...

And should you just want to try settings out on the fly, use xrandr. If you accidentally click into the System Settings/Display section or start krandrtray, then it can also put your display back to rights e.g. to get mine restored I run

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xrandr --output DVI-1 --right-of DVI-0 --output DVI-0 --mode 1440x900

and all is back as it should be (after killing the unhelpful settings module/krandrtray (or in the case of the latter, right-clicking krandrtray then unticking "Unify Outputs".

Phew, hope that helps somebody. My setup looks really, really nice, wobbly windows, desktop octahedron across both monitors, etc.. Shame it had to be done through xorg editing rather than through the peculiarly unhelpful System Settings/Display module. I still don't understand what that is for...

PS it may help someone on the dev side to know this:

(i) don't release KDE4.3 without this working in Display module or the disable the module - it looks really, really bad; and,

(ii) I noticed while writing this post and testing the krandrtray/xrandr recovery that when krandrtray started it defaulted to "unify outputs", which is clearly wrong and is an illogical starting point. Once you have unticked that then fixed the display with xrandr, the settings module called by left-clicking krandrtray recognises the existence of multiple monitors (although does not allow re-positioning). Go figure. You want a bug report, tell me where to put it.

To set up multiple screens i use nVIDIA tools and they work just great

If you are using nvidia card just start nvisia-settings as root, setup TvinView and save. Next time you log in, nvidia will detect screens and auto adjusts settings accordingly.

I do not believe a bug currently exists for the Display modules problems. Please file one at bugs.kde.org.

Bug submitted: https://bugs.kde.org/show_bug.cgi?id=201866

Note that lack of previous bug posting may be that those with less persistence may not realise that to find the right module to report against one cannot search on Display (although that's what I as a user would assume it is called) but rather randr (which I only guessed by searching for KCM following hint in bcooksley posting and spotting the randr module). Would recommend that is changed to assist in bug reporting.

If you're using an ATI card with the ATI driver you could try

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amdcccle

Interestingly I used to, but the upgrade of X broke the old ATI proprietary driver, and when the new one was released I just assumed it (a) wouldn't work with my card and (b) had worked out a manual way of doing it - but Kubuntu KDE 4.2 had no multiple monitors section so I also never tried to use that...

Also, back in 8.10 with the proprietary driver I had the same problem with dual monitors - that is, once configured, if you launched Systems Settings/Display it reverted the dual monitor setup to mirrored.

This has got to be on of the most annoying bugs in KDE right now.
I'll follow this thread for any updates...

I ran into the same problem. My solution was to install and run grandr, which could correctly set up the multiple monitor support and then suddently krandrtray started working as expected.