Use two monitors with one computer

I have two clients that want to use two separate monitors on one PC. They do not want a dual head video card because they dont want to have two desktops. We also dont want to spend the money on a dual head card, even though there are some relatively inexpensive ones, we want the ability to easily move the setup from one room to another.

Is anyone aware of a KVM or the like that will allow two monitors to be hooked to one PC?
Who is Participating?
Gary CaseConnect With a Mentor RetiredCommented:
You do NOT want to use a Y cable here -- as Callandor noted there's a voltage drop that will degrade both signals (and this happens whether or not the monitors are on).   ... and with one of the monitors a good distance away this issue would be even worse.

So ...  get an active amplifier that's designed to split the signal without loss;  the 8th item down on this page is a 1-PC, 2-monitor device;  there are several other choices on the same page (but the 1-PC, 2-monitor device does what you've suggested):

You indicated your client simply moves his wireless keyboard/mouse between desks.   If he's happy with that, then it's a perfectly good solution.   But you can also buy Y-Mouse and Y-Key adapters that will let you connect two keyboard/mouse combos to the same PC.   This might be a more convenient setup:
zephyr_hex (Megan)DeveloperCommented:
do they want to view the output on the monitors at the same time?  if so, a KVM will not work because it is a switch (you get one monitor or the other).
you would need a dual monitor graphics card.

if you want to move the setup from one room to another... do you mean move the monitors from one room to another?  or do you mean you want to be able to have dual monitors on more than one computer?  if you want to have dual monitors on more than one computer, you will need 1 dual monitor card for each PC that you want to have dual display.
if "move the setup from one room to another" means you are moving the monitors from one room to another.. why not just move the pc while you're at it.
ademboAuthor Commented:
zephry hex,

Thanks for you comments. I did suggest I do not want to buy a dual head video card. I am looking for alternative ways to do this without the card.

I am not moving anthing from room to room. The user has two desks in their office with one PC. The user wants to be able to move the screen from the monitor on his desk to the other. There is no need to have both screens on at the same time, as this is why I was asking about a KVM.

Typically, a KVM will allow you to use one monitor on two computers, but I want to do the opposite. I want to use two monitors on one computer, with the picture not having to be on both screens.

This may not be the easiest way, or typical way, but this is the way I am being given to make it happen.

Thanks for any additional help.
Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

A video distribution amp will provide you with a way to connect two monitors on a single port video card, but the image will be the same on both:

If you want the equivalent of an extended desktop using one video port, you will need a compatible video chipset and a DualHead2Go:
hi adembo,
there is something in your comments that can't quite understand:
 >>I am not moving anthing from room to room. The user has two desks in their office with one PC<<
what is your OS?
what do you mean exactly :the user has two desks..?
i know several possible solutions for this::
1)the user has a dual boot system:
--so you need to restart the machine everytime you want to access the other OS ,then you could just use a vga video switch : --> check out the SE-15V-2-2U1C model
2)the user has a virtual desktop application running under the OS,then your problem is application related and you should surely go with everykind of dual-head(i know you dislike this suggestion) GPU and set the desktops on a very display,it should surely work
3)the user makes an emulated OS a guest OS using :vmware or virtual pc,then it's just a matter of the right application settings;take the Callandor's suggestion or check out what does Nvidia /ATi have as a dualhead solutions,surely there are not so expensive and good solutions
4)the user is using an unix -based OS:so you have your all gamma of virtual desktops there;
i don't know haw it should work ,to have different desktops on differnt monitors and switch them ,but the most effective way to gain a wright answer is to check out the solution on a mailing -list regarding your distribution...
Did i even make a right guess?
if no,then please,give us more detailed information regarding this issue:
the user has two desks..

Nice time!

ademboAuthor Commented:

Yes, I did say the video can be the same on both. I am not trying to extend the desktop or do anything tricky here.

I apologize if I didnt give a very good description of what I am doing. I will check into the video distrubution amp.



You are a little over what I was looking for. Again, I apologize for not being more clear. I simply want the user to be able to turn around (being his other desk) and be able to work from there.

I do realize that I can accomplish this very easily with a dual head video card, but that is not what my client wants.

This is a simple Windows XP machine and a very large office that has two desks. He has very large "blue prints" that need to be layed out, and the information entered into the system from that. So he simply takes his wireless keyboard and mouse, and walks over to the other desk. He then wants to simply be able to enter the info into the computer, which can definately be the same screen as the other monitor. He does not want to have to worry about which desktop he is working on as with a dual head card.

Thanks for the info.
i think i got your thought,
now if you got an y-vga connector and get a cable extender for the other display perhaps you can achieve to solve the problem:
vga y-connector/cable:
check out this ,but pay attention for male and female connectors,perhaps you should buy also an adapter like: ,but let's hope not.
let's see what the other experts should suggest.
i think that this is your desired site:

The problem with VGA splitters is that if both monitors are on, the voltage will drop because it is a parallel circuit.  This typically results in a dark image, which you want to avoid, and the distribution amp boosts the signal on both so that this does not happen.
ademboAuthor Commented:

Thanks for the links.
From what I can tell you have a single desktop machine with 2 monitors probably flat panel monitors and they are propably facing back to back.  You then want either person to be able to control the same computer.  If this is the case you dont need a dual head video card all you need to do is install a video card that supports "windows xp dual video card support"  most simple mass produced video cards fit this description.  A few years ago I had to go through a few to find one that windows would detect both with but once you do its merely a matter of setting windows to show the same desktop to both monitors(this option is usually available in dual head video cars as well).  Then the person not using the monitor can just power his/her's off and the other person has full control. Hope this helps.

ademboAuthor Commented:
I bought a vga-splitter box for 20.00 and accomplished exactly what I wanted. As I stated, I did not want to extend the desktop onto either a dual head card or adding a second video card. I wanted the same desktop on two monitors, which the vga splitter did very easily and cheaply, in case anyone else ever is in need of that.

Gary CaseRetiredCommented:
As long as the signal is sufficient that you're happy with the results that's all you need.   In many cases the degradation from the 3db loss of the split is enough to cause problems -- that's why I (and others) suggested you should use an active splitter that amplifies the signal.

This is analogous to using a TV splitter to split a signal to 2 TV's ==> works in most cases for 2 or 3 TVs; but you rapidly reach the point where you need a distribution amp to eliminate the signal loss if you're using more TVs, or if the length of the runs is relatively long.
this is a very comprehensive addition to your answer suggestion,garycase;
which in fact can eleiminate furthur questions about :
-why i'm frequently loosing signal or
-why is it that in some cases my 'splitted'-display-system can't work as usual;
so in such cases there are no doubt that an active splitter is the more reasonable solution...
ademboAuthor Commented:
Im using this exactly as the box suggested by the instructions. I have a 15ft VGA to one 19" LCD and a 6ft to a 17" crt and the images look perfect on both screens. So what the box (which looks much like a KVM, but does not have the keyboard and mouse ports nor does it have to be switched between as it is active on both monitors at the same time) is doing, Im not sure, but all looks perfect. It has power running to it so it must be doing some type of amplification, otherwise it would be the same as using a Y-cable.


Gary CaseRetiredCommented:
If it has power running to it it's an active device -- in which case you did exactly what Callandor & I suggested (but found yourself a cheaper alternative than those we linked to).

I thought that little $50 350MHz bandwidth splitter was reasonably priced;  but certainly not as good as $20.   Do you happen to know the bandwidth of the splitter you bought?   ... and could you post a link?
ademboAuthor Commented:
Not sure of the MHz, I thought it was in the 800 range. I bought it at a local computer shop and have already thrown away the packaging. The box itself is just a plain brown metal box with the vga adapter for input and the two output. They had these that would handle up to 8 monitors. Not sure why you would want to have 8, but Im sure you can bet that someone somewhere wants something like that.

Thanks for everyone's help. I truly appreciate it.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.