Wednesday, January 14, 2009

Laptop + Multiple Monitors Help

I'm trying to get my laptop to display on dual external monitors. I'd appreciate some guidance in getting this configuration set up

What I have

  • A Dell Latitude D620 with nVidia Corporation G72M [Quadro NVS 110M/GeForce Go 7300]
  • A Dell docking station with dual-link DVI output
  • 2 Dell 2007FP Monitors
  • Ubuntu 8.04

What I want

  • When I dock my laptop, the two external monitors are used (I don't really need to use the internal screen as a third monitor)
  • When my laptop is undocked, my internal screen activates.


avilella said...

an option is to buy one of those replicators that would make the two screens looks like one unique long screen, that you will plug directly to the laptop. Then, the Nvidia drivers should be able to cope with it in Linux.

Martin said...

I have a similar configuration: 1 external monitor, connected via dvi and a laptop with dockingstation. I wrote a small script that reacts to the acpi lid event and uses xrandr to set the correct display configuration. You need a graphic driver that supports xrandr (me using xf86-video-ati).

Here is the script. It goes to /etc/acpi/local/


. /usr/share/acpi-support/power-funcs

for x in /tmp/.X11-unix/*; do
displaynum=`echo $x | sed s#/tmp/.X11-unix/X##`
if [ x"$XAUTHORITY" != x"" ]; then
export DISPLAY=":$displaynum"
grep -q closed /proc/acpi/button/lid/*/state
if [ $? = 0 ]
/usr/bin/xrandr --output LVDS --off --output DVI-0 --auto
/usr/bin/xrandr --output LVDS --auto --output DVI-0 --auto --right-of LVDS

I hope one day linux/xorg will get it right by itself without such hackish scripts :(

Steven Harms said...

I am using a Dell D620 also, but with Intel graphs and 1 VGA port. Works automatically, RandR takes care of it when the other monitor is plugged in automagically, only thing I had to do was edit the Virtual Size in xorg.conf.

Anonymous said...

If the docking station actually works, you can get it going. If not, the executive summary is that you're screwed. I can give you the long version if you like.

Assuming the docking station can be made to work, Martin is on the right track, but it won't work that way for you exactly, because you'll want to use the NVIDIA proprietary driver, most likely, and that doesn't support RandR 1.2. You could use the nouveau driver, which does, but you probably really don't want to do that.

The good news is the NVIDIA driver does actually support multiple monitor modes rather well. For a simple desktop with dual monitors at identical resolutions all it needs is two lines in xorg.conf.

For your situation it's a bit more complex. What you'll want to use is the driver's MetaModes feature, which lets you set up multiple 'modes' - like you want - and switch between them with a key combination. This is still not too hard to do. You can read about it in the NVIDIA driver documentation, here:

I find it pretty well-written and you should be able to set it up just going off that.

Anonymous said...

Ooops - sorry for multiple comments. I assumed there were two monitor ports on the docking station, or one on the docking station and one on the laptop itself and the NVIDIA driver will allow you to use both simultaneously. If not, see the executive summary. :)

Steven, Ben a) has NVIDIA graphics and b) wants *two external* monitors, not the internal laptop screen and one external monitor.

Ben Maurer said...

The port on the docking station is a dual link DVI, I'm hoping that a Y splitter cable will work here.

lewiz said...

you can't split dual-link DVI
you'll need to use the DVI-out on the dock and the RGB output on the laptop
from there you just use xrandr to enable/layout the displays

Adam said...

"Dual-link" does not mean "can connect two monitors" DVI comes in two flavors single and dual link, with DL giving you higher resolutions at higher refresh rates. (

If you *only* want to use your DVI output, what you will need is a Matrox DualHead2Go Digital Edition (

For Dell Latitudes if you get the Advanced D-Dock (the one with a media bay) it has a VGA and a DVI output and will drive two monitors just fine

Ben Maurer said...

Yeah, the dock I have does have the VGA output, so I can use that. If the box can drive two monitors, the dock should really give two dvi outputs...

Ran said...

Well there are 2 sides to this Matrox DualHead2Go; if you just plan to use the 2 monitors are 1 big monitor, then the Matrox should work just fine; however if you plan on using the 2 monitors are separate monitors as in you can run separate full screen applications, the only route would be to run one monitor on VGA and the other on DVI.

Multiple Monitor said...

Unfortunately, you can't use a spliter to unless you want it to clone the image. This will not give you an independent monitor. Also, I think most or all laptops are set to the master screen so you can't turn it off. Hey, at least you have a third screen. The more the merrier!

Dual Monitor said...

Since you have a Dual Link DVI port, you can get a Matrox DualHead2Go adapter that will turn your DVI port into two independent monitor ports. If you wanted three monitors, you could get a TripleHead2Go as well. Another cheap solution would be to get a USB to DVI adapter. That way you can hook one monitor to the docking station, and one in a USB port. You can find all kinds of adapters at Just go to the "Multi-Monitor Adapters" section. I hope that helps you out!

zygote said...

Can anyone advise me on how to have two external monitors set up using Windows?
I have a Toshiba Advanced Port Replicator III Plus which I know doesn't support both VGA and DVI simultaneously, and it only allows me to use the internal and one external monitor.
I've tried to plug in the VGA into the laptop directly - but to no avail. Remember I'm using Windows :(

Me said...

I've got the exact same setup.
D620, nvidia graphics, port replicator, and 2 Dells LCDs - one connected via VGA
the other via DVI. My port replicator has both a DVI and VGA output. I'm running Fedora 10, though I've had it configured this way since Fedora 6.
To get it working the way you want, I've got 2 separate xorg.conf files. I rarely undock so this isn't too much of a hassle for me. When I do need to undock I j
ust boot into runlevel 3, swap my xorg's then startx.

Multi-Screen said...

Check out getting a PC Express card to VGA adapter. You can use that and your external VGA to have two extra monitors. Also, check into a Triplehead2Go adapter. You can get just about any solution at