Space can be at a premium, especially if you live in a small apartment or have limited desk space. Having multiple computers can be useful. You can leave one performing a task in the background and not have to worry about it affecting your other computer’s performance – particularly useful if you have a work- and a gaming-PC. Having a separate monitor for each computer takes up a lot of space though, not to mention the other peripherals – thankfully, there are options to reduce the amount of hardware you need. You can use one monitor for multiple computers.
There are several ways to do this – here are some of our favourites.
Two cables into one monitor
Most monitors have multiple input ports in the back. You can connect both computers to your monitor at the same time using different cables. Then, using the monitor’s input selection, via the control buttons on the back or side (or remote control if it has one), you can choose which computer’s output you see. This only works for monitors that have multiple ports though – and you may have to pick different cables for the two computers. You can connect one via DVA or VGA port for example, and the other via HDMI – it depends on the hardware you have available.
Tip: Some ultrawide monitors offer the ability to display two computers at once, side by side. This feature is not available on all monitors though and is generally exclusive to modern, high-end, ultrawide monitors. If you have a monitor like that though, you can set it up to permanently display both computer’s output on one screen. Google your exact monitor model for instructions on how to do so.
This is a cheap way to connect two computers to one monitor but doesn’t solve the problem of other peripherals, such as mice and keyboards – you will still need two sets of each or constantly unplug and replug them. Neither option is ideal, especially if you need to change device regularly.
Hardware KVM switch
Another option is to use a hardware device called a KVM switch. KVM stands for “Keyboard, Video, and Mouse”. A KVM switch is a device that can control multiple computers through a single keyboard, mouse, and monitor. This saves you the trouble of having to have two sets or having to unplug and replug constantly. You will, however, have to buy an additional piece of tech.
The KVM will have a switch or button to choose which computer is supposed to have access to the peripherals. The switch can be flipped at any time to change which device is being controlled. In order to work, both computers need to be switched on. The actual switching usually takes only a few seconds – until your monitor has switched to its new input. You will also have to have your KVM switch somewhere you can easily get to it.
Price and functionality can vary dramatically from less than $20 for a simple two device switch to more than $100 for high-end devices supporting multiple 4k connections – the right device depends on your usage requirements. This option is the most space and user friendly; the only downsides are having to get the new piece of hardware, and the fact that the computers must be close enough together to be cabled into the same KVM. There usually isn’t a lot of spare cable, so you’ll have to have both machines fairly close together.
Remote desktop
Remote desktop connections are also an option. Programs like RDP and TeamViewer allow you to remotely control another computer, passing through keystrokes and mouse movements. This can be a free and simple solution, allowing you to remotely control one or more other computers from your main device. You don’t even have to be in the same country as the second computer – however, there are some issues with this type of connection as well.
The primary downside of remote desktop connections is usually the connection quality. Some connections may be bad enough that your inputs, such as keystrokes or mouse movements are delayed, although that level of lag is unlikely if the other computer is on your local network. Another problem is the screen clarity. It’s normally fine for generic browsing or word processing, as not much of the screen changes. However, remote desktop connections are heavily compressed, so the data can be transmitted reliably. This means that fast-moving images, such as videos or games can become a pixelated blur, and using graphic-editing programs like After Effects is nearly impossible.
Additionally, the second computer needs to be active and able to approve the remote connection – in many cases that means someone has to set up the connection on both computers before it works.
The right solution for you really depends on your situation. If you’ve got two computers next to each other, a KVM is likely your best choice. If you want to remotely control devices that are further away, especially if you’re only performing tasks that aren’t graphically demanding, a remote desktop connection may be preferable.
Ghulam Yasin says
LOL. I am using RDP and TeamViewer for the last 6 years. Today for the first time I need to have two PCs in my small office while I really do not have 2nd monitor right now. I forgot all remote approach and started to search for “how to use two CPU with one monitor”. Thankfully your article was at the top in SERPs.
Laughing slightly at myself.
Larry Williams says
Very helpful. I didn’t know you could switch inputs using a monitor’s menu.
Spud says
I have a question. Say I want to connect two notebook PCs to a single monitor or big screen TV simply to view what is displayed on each PC. Then I’d like to split the display so that each PCs screen appears on 1/2 of the TV much like a security camera setup. The trick is, can this be done wirelessly? I need to have one notebook in one room, another notebook in another room, and the display in a third room. Running cables is problematic at best.