Want To Add 3rd Monitor To Windows 7 PC.

Hello,   We have a user with an add-in graphics card on a Win 7 Pro X64 PC.   She has 2 monitors being serviced of that add-in card.   We want to add a third monitor.  The initial attempt to install the 3rd monitor was met by failure.   So, for several days, I have been working on other ways to configure a new 3rd Monitor:  researching issue on the internet, trying a variety of cable changes, graphics card changes, driver changes, use of specialized hub/connector and configuration changes.   Most of my testing has been on another PC, so as not to impede the user's productivity.  

I have found various technical articles indicating it is possible.   Including numerous instructional videos.   Most were for laptops and not desktops.  While informative, they have not led me down the path to success.

As it now stands, there is no way to get this to work, which seems due to existing hardware limitations.    it seems, a 3rd monitor might work if:

1)      The add-in graphics card supports 3 live monitors.   The one currently installed in the PC and test PC does not.  Having difficulty finding one that specifically does support 3 live monitors.  Even those with 3 connectors can only run 2 live at once.

2)      The PC has 2 identical add-graphics cards, running the same driver.   This is probably not possible, since almost all of the PCs we have purchased have only 1 PCI-Express slot, which will not allow for another identical graphics card.  I have test  with 2 graphics cards ans WIn 7 does not even allow using them with just 2 live monitors.  Windows just won’t allow both to be used.

3)      We purchase a new higher end PC with the needed graphics support supplied by the vendor.  This is questionable at best.  Unwilling to do this without guarantee it would work.

Please advise.   Thanks
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I have an Iomega DisplayLink certified USB 2.0 adapter.
Works great to add a second monitor to all my Dells.
Works great to clone one of two displays to a projector.
Didn't work great to replace the partially failed video card in a Precision Mobile unit as the driver is dependant on the presently installed hardware (i.e. no video card present and this unit doesn't work!)
Didn't work to add a third monitor to my OptiPlex 755.
Two monitors and a clone, yes.
Three independent, no.

If your mobo BIOS is built, set and determined that you are going to get video out on TWO monitors max, then that's what you'll get.  I've got a Palit card that I figured I'd add into a system to  get 3 monitors out.  Throw it in a Precision workstation -- Fine.  Throw the same card in my OptiPlex 755 -- forget it.

That's why the FIRST step is determining if your BIOS will support more than three monitors.  Because if it WON'T then it won't and that's the end of the story.
Sean ScissorsProgram Analyst IICommented:
Something like below will work for up to 3 monitors. It's the cheapest solution I could find that is a well known brand. Problem is though the size of the card itself. My guess is your current tower is a medium sized tower and these larger cards might not even fit physically.


Dimensions: 11.5" x 5.08"
Lee W, MVPTechnology and Business Process AdvisorCommented:
Ideally, you would have a motherboard with two x16 slots and then two graphics cards that support ATI Crossfire or nVidia SLI, but it should be possible with other configurations.  I've found this can be trial an error when the motherboard is limited as your is.

First. make sure your test PC is the same as the PC the end user is using to ensure configurations and settings can be matched up.

Second, Get a dual head card (if you don't already have one) and then consider one of the following options:
USB based graphics card
x1 graphics card

Try them both.

I use a dual card setup with SLI compatible cards but not actively in an SLI configuration.  Each drives 2 monitors and so I have 4 monitors in a quadrant configuration.  In the past, on a Dell Optiplex 320 (OLD system at this point) I was able to use a SINGLE dual head card and the onboard graphics as well - this gave me 3.  I also tried a SIIG USB graphics card which frankly annoyed me because the drive only let me logically position the monitor to the left or right, not top or bottom (or middle - at this point, I don't remember).  Also, while the 320 worked with the card and onboard video, I tried it with a 330 and that DID NOT - the newer PC couldn't use both a graphics card AND the onboard card at the same time - it was a pick one and use it configuration.
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Joe Winograd, Fellow&MVEDeveloperCommented:
> We purchase a new higher end PC with the needed graphics support supplied by the vendor. This is questionable at best. Unwilling to do this without guarantee it would work.

If you purchase a new PC with AMD Eyefinity technology, or perhaps even just a graphics card with AMD Eyefinity technology for the current PC, it is pretty much guaranteed to work, although I'm always reluctant to use the "guarantee" word in the computer business, as the YMMV principle often prevails. But to give an example, along with some explanations, I have an HP 8460w laptop in an HP advanced docking station and it supports three monitors, but only after I figured out the trick — when I first tried it, I could get only two monitors working. The solution was to get an active adapter, not passive. I first purchased this DisplayPort (male) to DVI (female) Active Adapter for one office:

It works perfectly. I now have three monitors working where before only two of the three worked at a time. For a second office where I was having the same issue, I purchased this DisplayPort (male) to HDMI (female) Active Adapter:

This also works perfectly and I now have three monitors working at that office, too.

The first two monitors are connected to the dock via DisplayPort and DVI. I'm driving both at 1920x1200. The third monitor may be either the laptop display or an external VGA monitor.

The StarTech website has a good explanation of why you need an active adapter instead of passive to get the three monitors working:

Also, the AMD website has this nice description (and other excellent material) of the basic requirements for connecting multiple displays:
Connecting multiple monitors for AMD Eyefinity technology couldn’t be simpler. There are four easy rules to remember:

1. The first two monitors can connect to the graphics card with any display output on your product: HDMI, VGA, DVI or DisplayPort.

2. The third (or greater) display must be connected to the graphics card via DisplayPort.

3. If your monitor does not have a DisplayPort connection, you will need an inexpensive active DisplayPort adapter for it. DVI to DP adapters can be had for less than $30 USD.

4. Every family of GPUs supports a different maximum number of displays.
Of course, the desktop PC or the laptop/docking station must have AMD Eyefinity technology for this solution. Regards, Joe
Gary CaseRetiredCommented:
Any card that supports Eyefinity will work fine.    As noted above, however, you will need to use an active Display Port adapter -- the passive adapters generally won't work for a 3-display configuration.

You don't need anywhere near as expensive a card as Sean suggested.   This would be a good choice:  http://www.newegg.com/Product/Product.aspx?Item=N82E16814150711&cm_re=eyefinity-_-14-150-711-_-Product

... or an even less-expensive choice:  http://www.newegg.com/Product/Product.aspx?Item=N82E16814161354&cm_re=eyefinity-_-14-161-354-_-Product
AaronSystems Administrator & DSTCommented:
This is the easiest solution...

HP USB Graphics Adapter by DisplayLink

It's a USB add monitor works with all GPU's that use 2 monitors that I have seen.
Joe Winograd, Fellow&MVEDeveloperCommented:
I suggest being careful about a USB solution, especially USB 2.0, which may not have enough bandwidth for good video performance. I think it would be preferable to go with a graphics card that has AMD Eyefinity technology, but if you want to consider a USB solution, I recommend StarTech's USB video adapters, which include DVI, VGA, DisplayPort, HDMI, and even a dual monitor one (HDMI and DVI):

Even though they offer USB 2.0 devices, get a USB 3.0 one. Of course, this means that the PC must have a USB 3.0 port to take advantage of the USB 3.0 video adapter. Regards, Joe
Gary CaseRetiredCommented:
Agree with using the StarTech USB adapters -- they work quite nicely; although I also agree that a single Eyefinity card is a much better choice.
As it now stands, there is no way to get this to work, which seems due to existing hardware limitations.
You have not yet stated what kind of machine / motherboard you are using.

From harsh experience I have learned that most Dell OptiPlex system motherboards will support ONLY TWO MONITORS.
This is a limitation of the motherboard BIOS.  You can add as many video cards as you like.  The system will support a whole bunch of CLONED monitors, but the extended desktop is only going to span TWO of them.

I have now learned to check prior to purchase to ensure that the machine I am buying will support the configuration.  The Precision workstations and some of the higher end OptiPlex (but only some!) will support more than two monitors.

What motherboard/system is involved here?

We purchase a new higher end PC with the needed graphics support supplied by the vendor.  This is questionable at best.  Unwilling to do this without guarantee it would work.


This unit has quad monitor support -- If you want MORE than two monitors, you MUST speak with a sales rep to confirm that you are getting what you need!

Of those subset of OptiPlex's that were triple monitor capable, only certain configurations work

And I doubt the limitations are Dell-specific, although, they are the ones that have caused me pain.  It is a recent development (3-5 years) that the BIOS became constrained to 2 monitors in some motherboards. I had never run into that with other systems.  If you could install the adapter cards, you could get video.  No more sadly, now it is caveat emptor.
AaronSystems Administrator & DSTCommented:
@Nick67- if this is a huge issue the USB adapters have ALWAYS worked after you install the drivers. With laptops or desktops and all are Dell that I have used and not "high end". This might be a good cost effective or temporary solution for this issue. They work with extended and duplicate display configurations. I have one user who has a laptop with 4 monitors (2 for a docking stations ports and 2 from these usb). Thats why I listed this as the solution though any brand should do nicely (check reviews) these have always worked great for me.

HP USB Graphics Adapter by DisplayLink
rstuemkeAuthor Commented:
Go it to work with out any additional cost.   My testing was on a similar, but not same model PC.  When I went to the actual PC I plugged the 3rd monitor into the integrated HDMI port and it worked.  Thanks for all the great responses.  I will split up the points.
Joe Winograd, Fellow&MVEDeveloperCommented:
You're welcome. And thanks to you for posting what worked, which, if I'm understanding it right, is that two monitors are connected to the add-in graphics card, and the third is connected to the built-in HDMI port. Did I get that right? If so, I'm really curious about this comment in your opening post:
The initial attempt to install the 3rd monitor was met by failure.
What was the initial attempt that failed? With two monitors already connected to the add-in graphics card, and an open HDMI port, it's hard to imagine that the initial attempt was anything other than connecting the third monitor to the open HDMI port. I'm really perplexed. Regards, Joe
My testing was on a similar, but not same model PC.
And it did not -- and probably could not -- work
When I went to the actual PC I plugged the 3rd monitor into the integrated HDMI port and it worked.

I've had that happen, too
Some Dell OptiPlex's will support three monitors, others won't.
And it's a BIOS thing, which cannot be remedied when you hit it
The BIOS addressing scheme of units that permit only two monitors allows for two independent monitors, and no more.
You can hook up three.
You can get video out of any two at one time -- but not three.
You can get a clone of one, and then two independent monitors -- but no extended desktop to three.
Drives a guy mad!

Joe Winograd, Fellow&MVEDeveloperCommented:
We'll see what the asker says, but my interpretation of his closing post is different from yours. His "testing" was on a similar model PC, but when he "went to the actual PC ", it worked. In other words, he first tested it on a different machine to make sure it would work, and then he went to the actual machine with the problem previously, and it worked there, too. Just my interpretation, of course, and I could be wrong. Regards, Joe

UPDATE: I just had a different thought on this. Maybe the asker is saying that it failed on his "similar" PC, but worked on the "actual" one. If so, then Nick's comment is spot-on!
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