Best KVM Switch
A KVM switch (or keyboard/video/mouse) is a device that lets you easily swap input devices between two or more computer systems. The basic design of this type of switch has input for a keyboard and mouse as well as a connection to a single video display. This then connects to the keyboard/mouse ports and video output on multiple computers. With the press of a button on the switch (or hotkey if you prefer) you can then use one keyboard, mouse, and video display, easily swapping between the computers you have connected. While this certainly isn't necessary in every computer setup, a KVM switch makes multitasking easier between multiple workstations and using one setup for more than one system.
We've chosen the following best KVM switches because they all provide the best functionality due to support for at least four different computers, though switches with even more ports are available. All of these are great options for the latest computers and displays, thanks to either DVI or VGA and USB support although they're not all ideal if say you need an old PS/2 connection for the mouse and keyboard. These picks also don't require additional software for their installation.
TRENDnet 4-Port DVI USB Type A KVM Switch with Audio - TK-422DVK
IOGEAR 4 Port VGA KVM PS2 Switch and USB - GCS1724
Tripp Lite B006-VU4-R 4-Port Desktop KVM Switch
IOGEAR 8-Port KVM Switch GCS138KIT
D-Link 4-Port USB KVM Switch (DKVM-4U)
A lot of smart decisions went into designing this KVM switch and it all comes together to make a really effective and easy-to-use switch. This model works for up to four different systems that you want to connect with each one clearly marked on the front buttons and back connections areas. This model has USB ports for the mouse/keyboard and DVI video ports for the monitors. If you need VGA this isn't a great choice, which is perhaps its only real weakness. However, it has microphone and speaker plugs for all four systems, and two additional USB ports for connecting storage devices or printers. The switch buttons are easy to see and press, though you can also use hotkeys to switch between systems. LED lighting clearly indicates which system is currently active and this kit even includes all the necessary cables, making it easy to set up with minimal effort.
There is a lot to like about this model from IOGEAR although it lacks the extra audio connections of the TRENDnet TK-422DVK. This switch uses VGA connections for the video which is perfect for use with most modern displays and monitors. Perhaps the best feature of this model is it works with either USB mouse and keyboard connections or older PS/2 plugs. Also included are four cables which have VGA, PS/2, and USB connections for easy setup. However, another set of cables is needed to connect from the switch to console, so keep that in mind while shopping. That's an odd oversight, but otherwise everything you need is included with this set. The large buttons are on the front of the switch, plus you can use hotkeys or a mouse to switch between systems. This model has no additional power requirements so you don't have to worry about having a free outlet to use it.
There are some good features included with this KVM switch, but also a few aspects are less than ideal. Perhaps the strangest thing about this switch is the USB console connections are on the front of the switch while the display connection is on the back. While not a major issue, it just seems strange and is not as streamlined as some other models on the market. This switch is pretty easy to set up and use although it only supports USB keyboard and mouse setups and VGA monitors. Keep in mind you need to plug in a power supply with this model and it doesn't come with any cables. The steel housing is good and strong, so you're getting a durably built device, the buttons are easy to press, and it supports hotkeys to switch between systems.
While a lot of KVM switches are designed to connect just a few systems, this is a great option if you're looking for something much more extensive. This is an eight-port switch you can use to connect eight different systems to a single mouse, keyboard, and monitor. If that's still not enough, you can use more than one of these switches together to control up to 512 computers all with a single keyboard, mouse, and monitor. It also has an on-screen display that lets you keep track of what computer you're currently accessing.
Keep in mind, this pick is designed for a mouse and keyboard with PS/2 connections (rather than USB) and it uses VGA video ports. You can use this switch on a desktop, but also designed to fit into a rack for professional use. Eight connection cables are included, four of which are six feet long while the other four are ten feet long. This switch is definitely not for an average home setup, but it's a great choice for professional rigs with even hundreds of systems.