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Some video cards have two vga outputs. But how to have more than two monitors?


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Remember that VGA gets a bit blurry. I had a quad-20" once where two was on DVI and two on VGA, and it was pretty obvious where the VGA-monitors where. – Commander Keen May 29 '09 at 13:20

16 Answers 16

up vote 5 down vote accepted

You can either use multiple video cards or can check out the Matrox TripleHead2Go or DualHead2Go.

Try hyperlinks or – drozzy May 29 '09 at 13:19
I did use the Serverfault Hyperlink generator, but something seems to be amiss. Let me edit it and try again. – user2626 May 29 '09 at 13:50
Much better. I linked directly from the google page, and that seems to break the hyperlink generation. – user2626 May 29 '09 at 13:52

Yes, to achieve that you need to add another video card, mind you it's recommended to have 2 cards from the same vendor. Or you'll get some incompatibility problems later on.

Jeff has blogged quite clearly about that,

Don't forget to use ultramon,

Welcome to the world of multiple monitors, =)

+1 for ultramon – Antony Jul 4 '09 at 10:03

Add another video card.


There exists VGA splitters that take a single VGA output and emulate a huge resolution which is split on two or three other screens. Matrox makes these I believe.

Another way is to go SLI, that will allow you to go up to 4 VGA outputs.

SLI combines multiple video cards into one for the processing power. You can run multiple video cards and each has their own monitor or two. The setup I have is dual 9800GT SLI, but they only drive two monitors from the main card. If I wanted to use all four ports on these two cards for four monitors I would have to disable SLI. – steve.lippert Jun 17 '09 at 15:36
You are right that SLI has to be deactivated on the software side but you still need an SLI motherboard :-) – Antoine Benkemoun Jun 17 '09 at 16:44

Take a look at Matrox website - they have triple- and quad-head video cards. You can also use more than one video card in a single computer - not in SLI or Crossfire mode. Of course your OS must support such configurations.


I've always used the multiple videocard approach. It has worked for me on both Window (XP) and Linux (RedHat) platforms. For laptops there are USB 2 Video solutions available, but I've not had to use them.

On linux, I've had to either have a dual-display video card, or circa the late 90's needed to run the latest XFree86 in xinerama mode. I used dual matrox millennium II cards back then. I had to play with the X11 display config file a bit, but generally got it working after a few tries. We even got a server to display 4 displays in our NOC at the time.

I'm currently using WinXP with an Nvidia Quatro PCIe card and a radeon 7500 PCI card, each with two displays (though I only have 3 panels). It took no difficulty in configuring at all.


This depends on your hardware setup. Most current moderately priced workstations now have the capability to support 4 monitors. Usually four is all you need. Anymore than that and sometime of mounted monitor rig would need to be setup.

If you have a machine with multiple PCI/PCI-x expansion slots, all you need to do is buy more graphics cards with dual output. I currently have a machine with two PCI-X graphics cards. Each card has two video outputs. I have four monitors.


To add more than 2 monitors, add some more video cards.

However, let me share my experience:

I used to have 4 big CRT monitors stacked up in front of me. Besides getting a radiation tan every time I came to work, and living in continual fear of an earthquake :), it was hard to work with, as none of the monitors was in an optimum position for viewing.

I now have one screen that monitors my server logs, and my main screen with 5 virtual desktops. (I use Ubuntu, so I have them all on a pretty spinning 5-sided-cube :) ) I find this setup MUCH easier to use than the 4 monitor apporach, and much more practical.

OR - If it's the 360 degree option you're trying to acheive - see this


Use multiple video cards. Some video cards (matrox for example) have two outputs, or one high-density connector (Dell for example) that splits using a converter. Multiple cards can be fitted to provide multiple displays.

Why? Flight simulator games (front, left, right, lowered front and elevated front displays) :O, presentations - exhibitions etc, graphic manipulation (one for working, one for the calibrated display of the final image, and one for palettes), 3d rendering (one for mesh, one for render, one for palettes). The largest multiple monitor scenario I saw was done by an IBM reseller who had a 'Wall of Windows' at erm.. 12 wide, but 8 deep? Why? Because they could.


You also might want to look into pre SLI'ed or Crossfired(I think these exist) cards. Basically they combine the two cards for you so you don't have to shop around for ones that work in SLI mode, and you just need the two PCI-express slots to plug them in. Usually they come with more than 2 ports in the back to plug in monitors.


The nvidia Quadro NVS series cards (specifically the 420, 450, or the older 440) support 4 monitors in a single card.

ATI offers similar products with their FireMV series, but I have never used them.


I would recommend using DVI for multimonitors.


If your computer has no additional slots for a graphics card, you could use a USB based DisplayLink adapter. I use this every day, and can 'take it with me' to use on my computer at home...

I've seen these in the stores. I presume they'd be no good for video, but are they useful for other day-to-day uses? – David Mackintosh Jun 17 '09 at 15:32
Yes, streaming video is poor. That was the reason I purchased the device. I bought th IOGear DVI Net ShareStation to connect my computer to our 42" 1080p TV. My wife was getting neck cramps sitting at the computer watching streamed ABC TV shows. Works great at my office. I have two computers and two monitors; I connect both monitors to one PC and then start a Remote Desktop to the other. I now use one keyboard and mouse, and can span two screens for my LabVIEW application development. – pbrooks100 Jun 18 '09 at 14:38

Be carefull with the Matrox Dualhead option as they don't provide true screeen behaviour. What they do provide is an emulatiion of a very wide screen monitor. It really annoyed some of my users when they try to maximise an application on one screen and it expands acroos both. I wouldn't look at Dualhead again as a solution.

As an aside once you move to dual monitor you'll wonder how you ever survived without it.

I also use virtual dimension to give me extra space, I have 5 desktops which gives me the same as 10 monitors (kinda :-). It does promote a bad habit of not closing stuff down though.



To do 4 monitors on one computer is pricey. First you need to request A custom build computer case, then you need A motherboard that supports 2 PCI-E cards, then the pci cards have to dvi outs on eatch of them


You can do 4 stadard low end cards with A system that has 4 slots open on the main board.. Eather way it's some thing you build before you buy A system, so that system will met your basic needs


Just throwing this out there, google karma.

Turn off the Matrox.Pdesk.ServiceHost services, I think installed by some Windows Update.

My Win2003 was causing Outlook to chew cpu whenever I moused back into my machine's monitor (I use Synergy+). Although it doesn't make sense, I think that was somehow related to the Matrox services. I noticed Matrox.Pdesk.ServiceHost.exe and/or Matrox.PowerDesk.Services.exe consuming a gig of memory, though I don't know if that memory usage was consistent -- I always saw delays mousing back to my main computer monitor when Outlook was the focused window.

Anyway I wasn't using Matrox powerdesk/virtual screen features so I disabled those two services and everything seems a lot better.


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