Regarding External Displays and Conference Presentations

By | 2009/05/01

Warning: This post is a rant regarding external displays and projectors. If you’ve ever been frustrated and want a possible solution to keep in your back pocket for your next presentation, read on. If you are a hermit, never leaving your mothers basement, you can go back to whatever it is that you do..

I was just trolling the interwebs looking for something to entertain me, and I came across a video of a conference presentation. I was bored so I clicked play, and then spent the next five minutes (as did the audience at the conference) waiting and watching as innumerable nerds tried to get the projector working. This is ridiculous.

How many of you have presented at a conference, Linux User Group or other such forum and had trouble with the projector? I know I have. I had issues when I presented at OSCON just this last year, and I think I’ve had trouble at just about every conference I’ve been to.

This not only makes the presenter and organizers look bad, but in turn make Linux look bad as well. We spend all of our time talking about how Linux can do everything just short of save humanity from itself, yet we can’t tell you how because we can’t get the damned display to use the projector!

I want to outline two simple steps that I’ve used to get mirrored output on additional displays. This includes external LCD/CRT monitors, projectors, etc. I have had success with this on a number of machines as well. It should work for you, and please try this at your next presentation. If not to make Linux look better, but to make yourself and your presentation look more professional (I can’t help you with your content however).

xrandr --output VGA --auto

Anytime I have needed mirrored display between a laptop (most commonly used to present with) and a projector or external display, those two commands have come through for me. Now, I’m not promising extended display. I’m not promising perfect maximum resolution, but I am promising actual video coming from the external display.

The xrandr command should be standard on most any distribution, and should properly find the available resolutions of any hardware output (ie; LVDS, VGA, etc). The only potential issue I see with this method is that the projector can’t support your resolution, which can be bypassed by lowering your resolution to that of the projector and running the commands again.

Ohh, and my biggest piece of presenting advice is please, please do a practice run with a projector or external display *before* the big day. That way you can test this (and other) methods before you’ve got a hundred people watching and waiting.

16 thoughts on “Regarding External Displays and Conference Presentations

  1. james burkle

    Thanks, I know I've had trouble with getting my laptop to output to a projector in the past, and I'm sure this will come in handy in the future.

  2. Mackenzie

    Thanks! I’ll have to try this. I know the button for output switching is currently non-functioning (have to learn how to fix that this summer…), but this seems like it’ll bypass that issue.

  3. RantingRaver

    I use lxrandr:
    sudo apt-get install lxrandr

    Run it from the command line. It's a simple little gui for this exact purpose. Works perfectly.

  4. Chris

    I was presenting a slideshow presentation in my college speech class about the benefits of using Open Source software, especially Linux. It was incredibly embarrassing trying to get the projector to work, mostly because I was trying to show the benefits of using Linux. Thanks for the commands, I'm going to try those out!

  5. Darwin Survivor

    I haven't had any troubles with my current laptop, but I was wondering if this worked with new nvidia cards using the binary drivers. I can't configure my display using the standard ubuntu tools under System->Administration, instead I have to use nvidia's config program.

  6. Mats Taraldsvik

    @Darwin : I don't think the binary nvidia drivers support xrandr – which is why the standard ubuntu tools, that depend on xrandr (?), won't.

  7. Mats Taraldsvik

    won't work, that is… 🙂

  8. Mike

    I've had excellent success as of the latest couple of distros with the display manager in System > preferences.

    Failing that, the atomic option has always worked: reboot.

  9. Confused

    What's wrong with Fn+F8 (or whatever F key your particular model uses)?

  10. Mackenzie

    The trouble is those are often ACPI events and so if your laptop’s ACPI module doesn’t have it implemented, you’re screwed. Example: asus_laptop has no idea what to do about the video output switch button. It doesn’t even generate a keycode.

  11. Confused


    Thank you for your response. I've used external displays on 4 different Linux laptops and always just used the F key combination. I guess I've just always been lucky. I don't like looking a fool, but I do like learning new things, so again, thank you. 🙂

  12. Eddie

    Hi Christer, these commands work like a charm!

    Yesterday I was trying to show to my students how to use Ubuntu using a 9.04 live CD in a laptop connected to a projector. After fiddling with Fn-F8 and whatnot without results, I remembered your invocation. It worked, and I was surprised of seeing *both* the laptop's TFT and the projector displaying the same image! (usually I just can get the external one going on)

    Many thanks, really a first-class incantation!

  13. Mackenzie

    I’ve been using this all summer for dual-head 🙂
    xrandr –output VGA1 –right-of LVDS1 –auto

    If i boot with the external plugged in, those 1’s aren’t needed. No idea why. When I tried your way to mirror it for a presentation last week, it didn’t work though. It turned out it was trying way too high of a resolution.

  14. Denny Lastpaste

    Hahahaaaa… I’m lol of it. Your story is pretty embrassing. It happed to me too:D
    But, overall this is amazing tips. My “System Settings” was stuck. Well, it will be alternatif for next presentation 😀

    Thanks a lot buddy 😀

Comments are closed.