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How can I use my laptop in a dual monitor environment (Not including laptop monitor)?

sciggs used Ask the Experts™
Below is our situation:

We have a truck rig that we take to customer sites and tradeshows with (2) 42" screens in it.  One desktop is connected to these screens with a Matrox Video card that supports dual monitors.  We are wanting to get rid of this desktop (stays in rig 24/7, heat/environment issues) so anyone with a laptop can hook up to the monitors and demo our software on both monitors.

I recently purchased a Matrox DualHead2Go hardware appliance last week but it did not work as described or how I wanted.  It only allows for you to stretch your screen across the 2 external monitors, not use both of them separately.

I am wanting to use Monitor 1 as my main desktop, and monitor 2 as my extended desktop (I do not care what the laptop is displaying as it will probably be closed).  I just want to use it as an extended desktop setup between the 2 external monitors.

Does anyone know any hardware/software solutions that could work for what I am trying to acheive?  Upgrading the video card is not an option.

Thanks in advance for any help.
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the vga output signal is limited by the laptop's internal video adapter, no matter how u configure the external monitors / devices, u cannot go beyond that limit
is half of the resolution good enough for your use on one monitor? if yes, u can find a video signal splitter (like the one used for combining several monitors to form a big video wall) to separate the output into two monitors.
Cameron YoungIT Manager

Anyone with a laptop means the laptop users need notebooks that support dual display. There are plenty of notebooks that do using a docking station for instance... but can I suggest this instead, get a little micro PC, something economical and fan less, then get a solid state drive for it. Then you have no moving parts, no environmental or vibration issues, its small enough to be mounted out of sight, and you can have a permanent solution.

Using laptops is just going to cause more problems, have you ever seen an exec trying to get their laptop to work in a meeting with a projector? Well good luck with dual display.
Top Expert 2011
Your laptops will / should obviously be able to provide your external monitors with the required resolution, but what type of monitors do you have?  You did not say.  If they are LCD type, their "native" resolution must be considered.  You don't want your software demo to look blurry because your output is in a different format than the native resolution of the larger LCD monitor / projector.

<<<< It only allows for you to stretch your screen across the 2 external monitors.>>>>>

This is what I understand an extended desktop to be.   Extending your desktop real estate over the area of two monitors.

<<<<......, not use both of them separately>>>>>

This is not.

By saying "use both of them separately", you mean mirrored or the same image on both external screens simultaneously, correct?  (I was understanding this is what you wanted as opposed to "stretching your screen across two monitors")

What you want is a "powered splitter".  It takes a single output and amplifies it to two or more separate outputs.  (Two in your case)

For example:

2 Port XGA SVGA VGA Splitter Amplifier Monitor Splitter 450 MHz

This product is a signal booster and duplicator which can take video input from a single source, broadcast and display it on two VGA monitors in a distance up to 180 feet (60M). It features a signal bandwidth of 450MHz. High resolution setting of 2048 x 1536 in 24 or 32-bit true color mode will also secure the high quality of the video graphic images to be displaying. It's ideal for an environment of education, meeting and commercial demonstration.

# Supports 450 MHz video bandwidth
# Supports resolution up to 2048 x 1536 at 60Hz
# Supports SVGA, VGA, XGA, and Multi-sync compliant monitors
# Amplified video signals for distance up to 180Ft (60M)
# Can be daisy-chained with multiple units generating more outputs
# All metal casing
# Input: DB15HD female connector
# Output: 2 x DB15 female connector
# Power supply included (DC6V)
Your laptop should have 1 VGA connection on it which you can use; I've used USB to VGA adapters in the past. They're not as good as a dual port video card but they get the job done. There are several out there; I just did a quick google for it and found this one:


So you'd use your laptop's VGA as the primary and your extended monitor would be the USB to VGA monitor.

Best of luck!
Gary CaseRetired
Most Valuable Expert 2013
Top Expert 2009
First, the simplest solution is what you've already tried -- BUT a better version of it.

The Matrox Dual-Head-2-Go and Triple-Head-2-Go units do indeed work by internally using a very high resolution, and splitting these across the connected displays ==> but the Windows display driver should see them just like any other multiple display setup.

HOWEVER ... a Dual-Head-2-Go doesn't support 2 1920 x 1080 displays => you'll need a Triple-Head-2-Go to provide that resolution.   Also, these don't work properly if you don't have a supported video adapter ==> so be sure to check Matrox's site to see if your adapter works with these, and, if so, what the maximum supported resolutions are with any specific Triple-Head-2-Go version and your display adapter.    You can find out what your system will support with each of the different versions here:  http://www.matrox.com/graphics/en/support/compatibility/gxm/

Another alternative is to use your internal video adapter to drive one of the displays;  and one of these external USB adapters to drive the other:  http://www.cyberguys.com/product-details/?productid=51038     But the USB adapters are sometimes problematic with high bandwidth material -- you'll need to try it in your application to confirm whether or not it will work well for you.
Gary CaseRetired
Most Valuable Expert 2013
Top Expert 2009

... one caveat:   If you decide to use a USB external adapter, be sure you get one that supports the 1920 x 1080 you need for the 42" displays.    [Not all of them do -- the one I suggested above, of course, does]


"<<<< It only allows for you to stretch your screen across the 2 external monitors.>>>>>

This is what I understand an extended desktop to be.   Extending your desktop real estate over the area of two monitors."

What I mean by this is that everything is stretched across the 2 screens.  Including the task bar at the bottom of the screen, desktop backgroud, and when you maximum a window it stretches that single window across both of the monitors.
Top Expert 2011

OK, I understand now, and I missed it when you mentioned 42 inch screens.  Can I assume these are LCD HD screens  (1920 X 1080)?

If so, garycase is probably making more sense to you than I am.  Am I correct?

Am I at least on the same page about what you want to do with the displays (being mirrored)?
Gary CaseRetired
Most Valuable Expert 2013
Top Expert 2009
The setups I've seen with the Matrox external adapters (Dual-Head-2-Go & Triple-Head-2-Go) did not "behave" that way -- they worked exactly as if there were two independent display adapters ... you could "clone" one display;  have one primary and one extended; etc.

Not sure why your experience was different -- eiither it wasn't configured correctly, or you were trying to use an unsupported resolution.    As I noted above, you'll almost certainly need a Triple-Head-2-Go to get dual 1920 x 1080 resolutions on your two displays => and that will only work if your laptop's adapter supports a high enough resolution (3840 x 1920).

Probably your simplest solution is to just connect one display to the laptop's VGA output;  and use an external USB adapter that supports 1920 x 1080.