Closeup of a KVM switch with VGA connections.
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If you run several computers, your array of mice, keyboards, and monitors can quickly get out of hand. KVM switches can reduce your number of peripherals to a minimum using relatively simple hardware or software. Let’s take a look at how they work.

What Is a KVM Switch, and How Does It Work?

In simple terms, a KVM switch allows you to switch between different computer sources (or computer cases) while still using the same keyboard, monitor, and mouse; in fact, that’s what KVM stands for: Keyboard, Video, Mouse. That means if you have several PCs you need to work with, you don’t have to buy separate monitors, keyboards, and mice for every single PC. Instead, you just buy one of each and use the switch to go from PC to PC.

That being said, the term KVM is a bit misleading, and while original KVM switches only handled those three, modern switches will often handle more, including things like audio and USB ports. There are even KVM switches that switch between only one input, such as this Gana 3-port HDMI switch, although these are usually referred to simply by the data that they handle, such as an audio switch or a keyboard switch.

So how do they work exactly? Well, in the old days, plug-and-play technology didn’t exist, so every time you wanted to change a keyboard or mouse, you would have to restart the computer so the CPU could detect any peripherals. While this isn’t the case anymore, KVM switches still do something similar in that they fool the CPU into thinking there is a connection so that when you do end up switching, it goes smoothly.

How it does that is a bit complex, but basically, it emulates the peripherals for the computer and constantly maintains a “fake” signal. When you switch, the KVM switch replaces the emulated signal with your actual peripheral’s signal, providing a smooth and unnoticeable transition.

Types of KVM Switches Explained

KVM switches tend to come in two main flavors: hardware and software.

Hardware switches are the most common and the kind you’re most likely to run into or use. For example, consumer-grade KVMs can usually switch between two to four sources, although some can go up to eight, and they tend to be marketed a bit more to those who run small offices or businesses. For large corporations, some of the biggest KVM switches can go up to 64 and are sometimes connected to a server running many virtual machines that several people need to access.

Besides just the number of sources you can switch between, there’s also the video type, with the most common KVM switches being for VGA. Thankfully, KVM switches with HDMI and Display Port are becoming more common, but they tend to be a little bit more expensive than the VGA ones.

Another option is how many monitors you want to support, with one being the most common option and three being available, although rare. Again, you’re not likely to find an HDMI KVM that handles two or more monitors, although the tech is becoming more common at the time of writing in early 2022. Maybe in a few years, we might see HDMI as the default, rather than VGA, at least in the consumer market.

As for software KVM switches, they’re also a bit of a misnomer, as they usually don’t support monitor switching and are therefore technically KM switches. They work by installing an application on your computer that allows you to directly control a mouse and keyboard on any computer that’s connected to your network. These tend to be pretty handy in large corporations with many servers that need to be checked by several different IT and admin folks.

Do I Need a KVM Switch?

KVM switches can be pretty handy for personal use, although you’re looking at spending around $50 at the lower end, such as for this PWAY KVM, it depends largely on your usage. If you find that you’re constantly going back and forth between two PCs, then the $50 entry cost might very well be worth it. Or, if you don’t have much desk space and can only fit one monitor, mouse, keyboard, a KVM switch can be an excellent investment.

An Affordable KVM Switch

KVM Switch HDMI 4 Port Box

Easily control four different systems with this KVM switch that supports HDMI connections and that won't break the bank.

One other option is to use a software KVM and just have an extra monitor running; that way, you at least save some space while also being able to functionally use your other PC source.

If you run a business that tends to handle a lot of servers or machines, then a KVM switch can also be very useful, especially software ones, as they allow you to remotely access devices, saving you a trip to the location.

RELATED: How to Control Multiple PCs With One Keyboard Using Synergy

Profile Photo for Albert Bassili Albert Bassili
Albert Bassili is a freelance writer at How-to-Geek with eight years of experience in both commerce and tech writing. He's been a life-long lover of all sorts of tech and gadgets and has been building his own PCs for just under two decades now and he has more gadgets than he actually needs. He's written for a variety of sites from SFGate to GameGavel.
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