Can a Monitor be connected to 2 computers at the same time

Hi, I have an extra monitor which I mostly use with my desktop thru its DVI connector. However I would like to use it also as an extra monitor for my laptop which sits on my piano. In this case I would use the extra monitor's only open port, which is VGA (which I would connect to my laptop using a VGA to Mini Display Port adapter).

Before I go out and buy the proper cable, I'd like to know, is it possible to keep that extra monitor connected at all times to 2 different machines? What happens if both computers are running at the same time? Which will it display? Does it favor DVI over VGA?

Does your monitor have a menu/button allow you to switch inputs?
Such as "Input 1 = DVI/HDMI" and "Input = 2 VGA", or such.

I have a Menu item called "Auto Source". When I go in, I can select "Auto" or "Manual".
It was set to Auto so I tried Manual and nothing happened. I wonder if its because it knows that nothing else is plugged in.
In the meantime, I read about something called a KVM switch. I dont know if that would be necessary in my case (?)

Put it on manual. You should be able to select which input to use from a menu.

A "KVM (Keyboard, Video, Mouse) switch" is used so two computers share the same keyboard/mouse and monitor. There is a button on the KVM you press to switch between computers. The monitor only needs to use one input.

However if your computers (desktop and laptop) have different video outputs, it might get complicated - because you would then be switching between a VGA and HDMI/DVI output from the computer to a (either VGA or HDMI/DVI) input a the monitor. There may be KVM switches that provide multiple video inputs/outputs. I'm not sure.

I should have thought of this - as I use one myself (however both my computers have the same video output (HDMI)).

CountryBumkin said:

However if your computers (desktop and laptop) have different video outputs, it might get complicated - because you would then be switching between a VGA and HDMI/DVI output from the computer to a (either VGA or HDMI/DVI) input a the monitor. There may be KVM switches that provide multiple video inputs/outputs. I'm not sure.

I should have thought of this - as I use one myself (however both my computers have the same video output (HDMI)).

Click to expand...

I cant believe I had not heard of KVM until today! Well to tell you the truth Im a bit weary of using the VGA output on that monitor..isnt that Analog? Wont be as crisp as the DVI will it? I guess in an ideal world there would exist a DVI splitter (like a Y adapter where I could have 2 incoming DVI signals into the monitor. One would go DVI to the desktop and the other would convert to HDMI or MiniDisplay at the laptop.
That seems like it would be simpler.... but not sure what would happen if both machines were on at the same time!

So practically and realistically speaking, I guess I have 2 options:

1. Get a VGA (aka RGB) cable that will convert to the MiniDisplay (or HDMI) format at my laptop.
2. Get a KVM switch that would connect to the monitor via DVI and would have 2 different connectors for my computers (1 DVI and 1 VGA). Set to AUTO, the monitor may be able to figure out which is switched on...i dont know cause Ive never used one.

Hmm, found this interesting thread that provides more info:
Samsung monitor video input problem - Hardware Canucks


,,,,and DVI/VGA KVM switches do exist but WOW, the price is crazy for this combined analog and digital technology!
Canada Computers | Computers, Computer Parts, Computer Componets, Hardware & Accessories

With the KVM switch you don't need to do anything with your monitor - as far as the monitor is concerned it will not know how many computers are connected - it will just display whatever is passed-through the switch.
The easiest KVM setup would be if you can convert the laptop output to DVI/HDMI to match your computer's video output. There are a bunch of converters here vga to hdmi - Newegg.com for under $10.

I use a 4-port KVM switch with 4 computers, one Keyboard, one Video and one Mouse. It uses USB Keyboard and Mouse, upgraded a couple of years ago from PS/2 Keyboard and Mouse. The Video is still VGA but there are adapters for VGA to DVI one can use if having only the DVI port on the monitor. One can use the green USB to PS/2 for the mouse but the keyboard has to come with the purple adapter for the same, doesn't seem to work with the after-market adapter.

You could use a Monitor only switch like THIS ONE

Kodi said:

You could use a Monitor only switch like THIS ONE

Click to expand...

I don't think that one you linked to will work for OP because OP says one computer has VGA out and the other is HDMI/DVI out. The switch you linked to only works if both computers have DVI. Unless I missed something in the description.

you can get a coverter to change DVI to AVG or HDMI.
Cheaper option than KVM switch

CountryBumkin said:

Kodi said:

You could use a Monitor only switch like THIS ONE

Click to expand...

I don't think that one you linked to will work for OP because OP says one computer has VGA out and the other is HDMI/DVI out. The switch you linked to only works if both computers have DVI. Unless I missed something in the description.

Click to expand...

Actually, maybe i did not explain myself properly. My monitor has 2 ports: 1 VGA. 1 DVI. I have 2 computers I would like to share it with. Ideally I would like to use the DVI as I believe it would give me a better signal. Or would it? Is there proof of that?

So I could plug this device to the monitor.
Plug desktop PC as DVI to DVI.
Plug laptop as HDMI or MiniDisplay to DVI adapter connected to this box.

Its a bit pricy but, would this work?

Maybe I should ask, will the VGA signal be less crisp than the DVI?
Im sending a laptop thats 1920x1080 to a monitor thats 1680 x 1050.
Just using its VGA port would be more simple but if the signal will be less crips, then maybe its worth the expense of getting a monitor switch where I can connect 2 DVI computers even if one includes an HDMI to DVI adapter in its routed signal...

Approaching This from Another Angle

Hey Guys,

I think I have found another way to approach this.
I noticed from my research that there are a ton of HDMI splitters out there and they are way less expensive than KVM switches or DVI splitters (which are hard to find and very expensive).

So rather than approach this in terms of VGA or DVI, I'm now considering getting a self-powered HDMI splitter box (cause I dont want to have to plug in another AC power cord). The laptop will connect to it directly in HDMI format. And the desktop PC will connect to it thru a DVI-to-HDMI adapter. The splitter will then send these signals thru a short HDMI cable that I will combine to a HDMI-to-DVI adapter on the receiving monitor.

Does anyone see any reason why this would not work? Its a couple of things to buy but it's a bit cheaper, doesnt require a power source, and its more future-proof than investing in a DVI splitter.

HDE 3-Port 1080p HDMI Switch Switcher Splitter Hub for HDTV - Supports 3D: Amazon.ca: Electronics

*NOTE: My only concern is that some of these are self-powered (like this one) while others require an external power source. I dont know why....

I am joining the party six years late but I have similar question. I am not seeking a solution but I am curious to know what will happen. I have a monitor with two HDMI inputs. If I connect two PCs to this monitor directly and if both the PCs are switched on. Would that damage the monitor? Would it create a garbled output on the screen?

Welcome to Eight Forums Think of your TV that you have multiple HDMI devices connected to (Set top box, DVD player, etc.). You use the menu to switch inputs to the source you want to watch. Same with a Monitor. If one PC only is on, the Monitor may auto detect that signal and display the active signal. If both are on, the monitor may default to a particular signal or port (IE: HDMI 1). Just use the Monitor menu to select whichever input you want to view. Switch between them whenever you like, etc.

A Guy

I do this on the monitor I am using to type this post Though I use one DisplayPort and 1 HDMI.

I simply use the onscreen controls to select the DP port for this desktop and The HDMI port for the Laptop.

I have also used a similar setup to run the Laptops screen, the monitor and my TV screen at the same time - to create a singe screen set

I also use the TV as a second screen for my desktop, again with the TV on HDMI and the monitor on DP. In this mode I can use the TV remote to switch between Desktop screen on HDMI1 or a HDMI switch connection to a satellite TV Box or a Blue ray player on HDMI2

None of the various connections has ever caused any issues

Thank you, @A Guy and @Barman58