First of all, I'd like to say that I LOVE KDE 4. It's the first desktop I show to any friend who hasn't seen Linux before. It's sharp...kudos to the programmers who pulled it off.

I do, however, have one problem that's preventing me from adopting KDE permanently.

I run linux on a Toshiba laptop with a 15.4 inch, 1280x800 resolution screen, and I recently found a 17 inch, 1280x1024 Dell monitor for next to nothing. I plan on using the monitor while working at my desk [I'm a college student], and just unplug it when I'm mobile. It works fine under Ubuntu [GNOME], after only a little tweaking. When I first tried it under KDE 4.3 [and 4.2 before that] I was impressed that it detected both monitors right away, but disappointed when I can't do anything with them but mirroring, which doesn't help me. Especially since both monitors use different resolutions.

Before you say that I haven't looked around enough, and that this question has been asked before, I want to be clear that I've done my homework. I've followed HOWTO's, compiled drivers and kernels, and tried every xorg.conf hack in the book. No dice. I've seen Xinerama mentioned several times, but never could figure out how to get it working [the video card on my laptop is an ATI HD Radeon 3650, so TwinView is out of the question].

Does anyone [maybe someone who knows KDE's display system better than I] have any advice on how to get this working? Maybe a guide on enabling Xinerama or something similar? I just want to be able to drag windows between my monitors, and use my laptop's screen as the main one. That's all that I need.

Thanks ahead of time!

You should be able to use the modules located under System Settings > Display to manage this. Not sure which module will be of most help.

Thanks for the reply.

That's what's confusing me. System Settings > Display only allows me to change the resolutions of both monitors. It also shows a diagram with both monitors layered on top of each other. The Multiple Display module doesn't show me anything but a message stating that it's for configuring multiple monitors, but I don't have multiple monitors connected.

Does anyone else have this working on an ATI card? Catalyst Control Center doesn't allow me to use a multi-monitor option either [Xinerama is greyed out].

Try using KRandRTray, which may have some options for this.

I have tried using KRandRTray. It only gave me the same options I saw in the display setup module. I can change either screen's resolution, or rotate/flip them...that's it.

Would screenshots help?

I have a script that handles it for me (since xrandr didn't detect the right settings automatically):

Code: Select all

xrandr --newmode "1280x1024_60.00"  109.00  1280 1368 1496 1712  1024 1027 1034 1063 -hsync +vsync
xrandr --addmode VGA 1280x1024_60.00
xrandr --output LVDS --auto --output VGA --mode 1280x1024_60.00 --right-of

I don't know if this is the best way to do it, but it works. The first line comes from running "cvt 1280 1024".

Well I appreciate the help you guys, however I was not able to get this working. It's really not a mandatory thing...in fact, it has become more of a problem than a help with schoolwork. Since I have to connect and disconnect on a constant basis, it's giving my X setup some serious grief. I may, in the end, not use the extra monitor. I just don't have the patience to set this up every time I need it. If anyone else has any advice, please feel free to chime in though.

On another note, I tried running both screens in Windows 7 RC, and they worked just fine. Though still not easily enough for me to switch to using it as my main OS. I hope this gets fixed soon...it could really be a deal breaker if someone tried Linux and KDE for the first time on a setup with two monitors.

I have exactly the same problem. Dual monitors plugged into a single graphics card one DVI and one HDMI. Both monitors work but they are only working as mirrored monitors. I want to be able to extend my desktop over both of them though.

The Display options and krandrtray both give me the same options and view. With the graphical representation of the monitors showing them overlaid and with no option to change it.

Does anyone have any ideas where this can be adjusted ?


Same computer and setup works fine on Windows.

The graphical configuration for this is currently lacking severely in KDE. You may be able to tweak the script provided by Hans above for your purpose.

I might be able to help here- I'm huge on multiple monitor setups, and I've been digging around for months on how exactly to get dual monitors working perfectly. (I've settled on KDE 4, because IMO, KDE has the best UI for multiple monitor displays I've seen yet. Namely, window management and panels. I've tried a variety of different WM/panel combinations, including writing my own panel.)

Firstly, if you have nvidia, you should certainly be using nvidia-settings to setup your dual displays using TwinView. (And if you'd like to automate this process, specifically with nvidia, check out disper.)

Secondly, Hans' method *should* work if you don't have TwinView available. You might need to tweak his script, though. (For instance, your laptop display might be named "LVDS1" instead of "LVDS.")

The first thing to do is check your currently available monitors:

Code: Select all

xrandr -q

That should give you all the names you need and your available resolutions. In fact, something as simple as this should give you your dual monitors (a slight tweak from Hans' code):

Code: Select all

xrandr --output LVDS --auto --output VGA --auto --right-of

But make sure you change "LVDS" and "VGA" to your appropriate monitor names.

You also mentioned you were having trouble being portable. You could easily write another script like so:

Code: Select all

xrandr --output LVDS --auto --output VGA --off

And run it when you disconnect your other display.

I've actually set up my computer illiterate sister with Kubuntu and three scripts containing roughly similar commands to allow her to use dual monitors with her television. (She has Intel graphics.)

Hi, I have a similar problem, so i don't start a new topic. I have a laptop (1280*800, identified as LVDS) and an external LCD (1920*1080, identified as VGA).
I would like to use it like this:
- VGA as the main screen (it should display the task manager)
- LVDS as the extension of the main screen to the left.
I set up it with this command:
xrandr --output VGA --mode 1920x1080 --output LVDS --mode 1280x800 --left-of VGA
Everything is fine except that the task manager is not on the external screen. It bothers me, because I want to use the VGA as the main screen for my work (it's bigger, it's in front of me on my desk while my laptop with the LVDS is "far away" on my left).

Thanks in advance for any help!

You simply need to create an additional activity I believe, and add the needed panels, etc. manually.