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I have an XPS 14z with Intel and nVidia graphics. The Intel card is connected to the laptop display only. The nVidia card is connected to the display port and HDMI port.

I am running bumblebee for limited optimus support (i.e. power-saving only) and realise there is no seamless way to enable dual monitor output with extended desktop at this point.

That said, since I spend quite a portion of my time at my desk with my laptop connected to my charger, what is the easiest way to bypass bumblebee and just enable the nVidia card and utilise my external display (and not use the laptop display)?

I am kind of hoping to configure my laptop in such a way that I can simply specify an xorg.conf, restart lightdm and have the external display used. Then, if I remove the xorg.conf and restart lightdm, the laptop display is used. (Or a similarly quick switching method).

I am happy to log-out and back in during the transition from external to laptop display.

I did try this really-quickly by specifying a simply xorg.conf with the nvidia driver specified, but the xserver seemed to complain about not finding the nvidia module. Other questions similar to this seem to relate to enabling the external display alongside the laptop display.

Many thanks for any help,


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up voting it.. where did you get this info The Intel card is connected to the laptop display only. The nVidia card is connected to the display port and HDMI port. As far as I know images generated by nvidia are transported through intel card. – Web-E Jun 19 '12 at 12:21
I can't recall where I read that, however, testing has shown that to get anything on the external display from the HDMI or the DP, I need to pass launch the application via DISPLAY=:8 <program name> (which I do after launching optirun nvidia-settings -c 8). I would be happy with doing just this, but then I have two cursors for one mouse and I don't want to mess around with second window managers and the like. I am just hoping to switch between laptop and external displays. – Whytey Jun 20 '12 at 1:44
@Web-E There are models where the HDMI and/or DP are directly wired to the nvidia chip. In my case, everything is wired to the Intel one though. – Lekensteyn Jun 20 '12 at 8:46
@Lekensteyn got that. :) – Web-E Jun 20 '12 at 9:36

I believe what your trying to achieve is using the nvidia functionality on your DM DISPLAY MANAGER which is LightDM, I read it on the bublebee wiki an its possible but there a warning about running nvidia on your DISPLAY MANAGER.Just read the bumblebee official site and wiki im pretty sure there the intructions there.

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Thanks. Do you have specific links on the bumblebee site? I have read that thing over and over and tried a few of the suggestions on their but I have had no luck. Maybe the specific suggestion you have will help? Cheers. – Whytey Jun 20 '12 at 1:46 – Web-E Jun 20 '12 at 5:16
The point is, running a full DM through optirun is not recommended because of the copy overhead. It's perfectly fine to use something like DISPLAY=:8 LD_LIBRARY_PATH=... program. See also – Lekensteyn Jun 20 '12 at 8:49
Hi @Lekensteyn, I understand your statement about using optirun and the overhead incurred. Is there the same overhead if you configure xorg.conf to use only the nVidia card and external display? That is my goal here. – Whytey Jun 20 '12 at 10:59
@Lekensteyn, thank you for responding. It seems that it is going to be far too hard for me configure this laptop to have both power saving and the ability to use an external display effectively (even though I am somewhat technically able, even with Linux). I thought I had done my research into this whole Optimus issue and done the right thing buying the XPS 14z but alas I am beginning to wish I had just gone the intel route! (Hopefully, the smart folks on the Bumblebee project figure out a solutions soon). – Whytey Jun 21 '12 at 5:28

Because the nvidia driver requires some proprietary libraries, you need to reconfigure your system each time you switch between nvidia and intel drivers. If you use Ubuntu, you can do this with the program update-alternatives. Alternatively, you can update your xorg.conf Files Section with the correct ModulePath and make sure that all your GL programs are started with the correct LD_LIBRARY_PATH. You can find the correct values in bumblebee.conf, look for the lines with LibraryPath= and XorgModulePath=.

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Would I need to start every program manually with the LD_LIBRARY_PATH? Or once I have my xorg.conf configured correctly and everything is just going through the external display, will it all just work fine? I will try your suggestions once I get home tonight. – Whytey Jun 20 '12 at 1:47
up vote 0 down vote accepted

It is possible to do multi-monitor on the later versions of Ubuntu (14.04 and up), using nVidia Prime.

It relies on the nVidia binaries and the nVidia card needs to be enabled to do it (which reduced battery efficiency) but it works very well.

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