What is a KVM Switch?

KVM Switch definition

KVM switches are devices that provide a single user or multiple users with reliable access to multiple computers including multiple video channels and a mix of USB peripherals. Some KVM switches are designed to connect to up to thousands of servers and users and are even plug-and-play, so you can add or disconnect users and servers almost as quickly as you can plug and unplug cables.

What does a KVM Switch do and what is it used for?

KVM Switches process multiple video and peripheral signals and provide a single output to only one screen, keyboard, and mouse - or vice versa (reverse KVM switch). KVM switching allows operators to quickly access several computing data sources or AV signals. The technology is operating system agnostic and transparent to all applications. Application scenarios include desktop switching in offices, medical imaging, broadcast, post-production, and command and control rooms. Many businesses use server rooms to securely store dozens or even hundreds of servers. This figure can rise to thousands in data centers. In this scenario, IT staff are able to control all servers that are connected to a KVM switch with just one keyboard, monitor and mouse. This saves a lot of time, allowing to complete even the most advanced processes with ease

KVM Switch uses

• Multiple computer control

  Save time by centralising control of your computers and servers with only one keyboard, monitor, and mouse. This helps to maximise productivity and viewing capabilities and improves situational awareness by enabling fast data-gathering from several computers simultaneously.

• Multi-user computer access

  KVM matrix switches allow multiple operators to access one to many shared computers, facilitating cross-functional data access for faster decision making and information sharing

• Multiple OS control

  KVM switches are OS agnostic and therefore provide access to various operating systems such as Mac OS, Linux and Microsoft Windows. This is extremely useful for operators who need to access several operating systems without extended switching times

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Types of KVM Switches

There are different types of KVM switches that are capable of transmitting various signals: VGA, DVI, HDMI, DisplayPort video signals, transparent USB 2.0 and 3.1, digital or analogue audio, as well as serial formats like RS232. KVM switches can be combined with KVM extenders, transmitting signals over CATx cabling, fibre optic cabling, or an IP network. KVM Switch types can be differentiate by the following criteria:

By type of connectivity:

Desktop KVM switches

Desktop KVM switches usually provide switching capabilities of between 2 to 8 source PCs to one or even two (i.e. dual-head) monitor(s). There are KVM switches for almost all types of display connectors including legacy analog VGA, digital interfaces like DVI, DisplayPort and HDMI. Desktop KVM Switches also provid connectvity for HID such as keyboards an mice over USB 1/2/3 or legacy PS/2. Some of them also provide capabilities of switching between analog and digital (embedded) audio in/out. Since they are usually not big in size, they can be put on a desktop or even moounted behind a screen (vesa mounting) or underneath a table.

KVM Matrix Switches (Connectivity over CATx, Fibre or an IP network)

KVM matrix switches are used to connect multiple users with multiple sources like PCs and servers. The term matrix derives from the fact, that users can access various different sources within one managed KVM network - creating a matrix of various switchable endpoints. KVM matrices usually provide a specific number of ports to connect all endpoints over a transmission medium which can be CATx or fibre, utilising either a proprietary transmission protocol or IP. KVM matrix switches are usually also combined with KVM extenders to connect all related machines and users over small to large distances (CATx: usually < 150m; Fibre: >150 m < 20km). There is a large number of different types of KVM matrix switches varying from central, fixed port switches to modular, card-based ones, or even zero-client based IP systems that do not require a proprietary central switching unit and provide greater scalability. There's a wide range of supported display, peripheral, and audio interfaces, such as analog VGA, SDI, Composite, digital DVI, DisplayPort, HDMI, USB 2.0/3.1, PS/2, serial formats such as RS232, Infrared, digital and analog audio and even more.

KVM over IP switches

IP KVM switches allow users to control multiple PCs over a network, from anywhere at any time, with integral IP remote access. These switches are used to monitor and control multiple PCs and servers either in a dedicated IP network, a LAN (Local Area Network) or even over a WAN/Internet. These types of switches are usually intended for medium to large installations and data centers that require several users to manage a number of computers or servers. Usually, KVM matrix switches are combined with KVM extenders to enable access from multiple consoles throughout multiple rooms, buildings or even sites.

Find out more about Black Box KVM over IP Switches:

• Emerald^® KVM over IP (or direct connect), 4K60Hz Switch/Extender

• Agility IP Matrix Switch

By type of signal distribution:

HDMI KVM Switches

HDMI KVM switches provide HDMI signal switching without compromising video quality. These switches offer fast switching times without delays. They are ideal for applications such as broadcast, high-end medical imaging, interactive digital signage, home theatres, and even industrial automation.

Find out more about Black Box HDMI KVM Switches:

• KVM Extender – 4K@60Hz, HDMI 1.4, USB 2.0, HDBT 2.0, CAT5e/6/6A

• CATx KVM Extender – HDMI, USB 2.0

DVI KVM Switches

DVI KVM extenders are designed to provide a reliable digital video experience, overcomming the limitations of legacy analog formats such as VGA. These types of switches can support single-link or dual-link DVI-D or DVI-I and can even provide backwards compatibility to analogue VGA signals using a passive or active video converter. These switches are ideal in critical enterprise-level applications where reliable digital image quality and fast switch-over of redundant hardware are required, for example in broadcast playout centres, process monitoring and control, staging labs, and data centres.

Find out more about Black Box DVI KVM Switches:

• USB DVI KVM Switch, DT-series, 2-/4-Port

• DCX Digital CATx KVM Matrix Switch

• 4Site flex - Multiviewer KVM Switch

• DKM FXC, KVM Matrix Switch

DisplayPort KVM Switches

DisplayPort KVM switches are specially useful for peripheral sharing when users need to  share more USB peripherals among all computers. Like this, it's possible to use one set of keyboard, mouse and monitor to work on one computer while USB peripherals are connected to other computers. This helps to access high-performance graphical workstations and critical video processors from secure and temperature controlled equipment rooms while maintaining the same user desktop experience for editors, 3D artists and control room operators.

Find out more about Black Box DisplayPort KVM Switches:

• Emerald KVM over IP (or direct connect), 4K60Hz Switch/Extender

• DT DisplayPort KVM Switch, 2-/4-Port

• DCX Digital CATx KVM Matrix Switch

• Wizard DisplayPort KVM Switch, 4-Port

VGA KVM Switches

VGA KVM extenders are ideal for an affordable smooth real time switching experience and are capable of switching up to 1920x1200 VGA signals. These switches support dual, triple, or quad VGA video connectors, providing you with easy access to video heads on each channel.

Find out more about Black Box VGA KVM Switches:

• Wizard Multi-Head VGA + USB KVM Switch, 4-Port

• EC VGA KVM Switch PS2-User PS2/USB-CPUs, 4-/8-/16-Port

• DT Basic II VGA+PS/2 KVM Switch, 2-/4-Port

• DT Pro II VGA KVM Switch, 2-/4-Port

KVM Switches benefits and applications

There are many things to look for in a KVM switch such as single- or dual-head support. Main benefits of this technology include:

• Safeguarding Network and Cyber Intrusion through Secure KVM switches

Secure KVM switches are devices that allow network access at different levels of security. This prevents unauthorized network access and ensures multi-domain data isolation, as well as restricted switching and partitioning of video and data. By being capable of isolating between a secure network and a non-secure network, users have access to both systems from one user station thus saving space and costs. Users can securely manage, troubleshoot and configure IT equipment typically found in remote offices and IT racks - including servers, blades, switches, routers, network appliances, PBXs, firewalls, load balancers and power distribution units. This is specially important for command and control operations, including government, military, and defense. The most important features of secure KVM switches are secure port switching, data channel isolation, restricted USB connectivity and user data protection. Find more about Black Box Secure KVM Switches.

• Dual Monitor / Multi Monitor KVM Switching Setup

Dual and Multi Monitor KVM switches can be found amongst both single user Desktop KVM switches and KVM matrix switches. This feature allows users to have an extended desktop experience and at the same time easily access all of the connected computers from a single console.

• Multiple PC Setup

  There are many tasks which can only be completed or completed far more easily, using a certain type of computer. An example would be a piece of software designed specifically for Mac OS. Furthermore, it is common for users to have a laptop or notebook for mobile use, and a PC for home use. By investing in a KVM switch, users can switch between two different types of device.

• Extended Desktop Experience without compromising on CPU processing power

  Those who use computers for demanding tasks like high-definition video editing often find that they need a computer's full power to do it effectively, meaning that it would be detrimental to use their computer for other tasks. In 4K post-production scenarios, high-performance workstations must be used at their full power for an effective job. By switching between multiple computers connected to a central storage solution, multiple users can share access to dedicated workstations for editing, colour grading and visual effects. This helps to safe money for hardware and software and makes editing workflows much easier.

• Server-Console management and Network Troubleshooting

  KVM switching enables IT staff to easily access various servers in an IT/server room and perform remote device management, autodiscovery of new units, user access control and logical device grouping.

• Software Testing on a Multi-OS Setup

  KVM is also crucial when testing products like software applications. Product developers might have the need to undertand how their products work on various operating systems to make sure it works to their liking on all of them. A KVM switch allows to quickly switch views between several operating systems like Windows, Mac OS, Linux , or Ubuntu. KVM switches allows to test software on a real system without the need for any additional hardware resources.

• Remote file management

  In combination with KVM Extenders, KVM switches enable a remote user to effortlessly share files from a mass storage device located on their desktop — a USB flash drive or an external HDD, for instance — to multiple accessible computers. Cost savings are realised through reduced downtime and less travel.

• Virtual Remote Desktop and Virtual Network Computing

  KVM over IP Switching with Black Box Emerald Unified KVM allows for multiple virtual remote desktop sessions in order to control multiple servers from one user station. It allows high-speed access to applications like OS patching, software installations and diagnostic testing. Operators can map DVD-CD-ROMs and other storage media to a remote server, control multiple connected servers from the same login session or even access and distribute virtual media with data encryption.

• Safeguarding critical computing equipment in a secure and temperature controlled environment

  Combined with KVM extenders, KVM switches provide access to multiple remote servers/ PCs from a single peripheral interface whilst the critical computing hardware is secured in a temperature controlled environment away from the user workstation. Operators enjoy the same desktop experience but with less noise, heat and clutter.

What is the best KVM Switch for me and what factors do I need to take into account when choosing?

It's important to carefully consider what is the best KVM switch for your configuration depending on your application requirements and the switch features. In order to find the best KVM switch for your configuration here are the major questions to consider:

• Existing PC Setup
  • How many CPUs do you currently need to connect? Do you expect this number to increase in the future?
  • What keyboard/mouse connections do your CPUs have? PS/2, USB or both?
  • What types of peripherals need to be connected? Is audio switching required?
  • How many users are there? How many users will need to control and access multiple computers simultaneously?
• Required Video Formats
  • Which video interfaces would you like to connect? Digital (DVI, HDMI, DisplayPort, SDI) or analog (VGA) video?
  • What are your video resolution requirements?
• Connection distance
  • What are the distances between the users and the computers? Do you need to add an extender to your setup?
• Level of computer access security required
  • Do you need to provide selective computer access and information transfer based on strict security classification levels?
  • Do you need special network security features like prevention of unauthorized access with password security?
  • Do you need special network security features like tamper-resistannce and intrusion-detection?
  • Do you need to prevent data transmission from being buffered and leaked from one classification level to another?
  • Do you need to ensure data isolation?
• Network management and troubleshooting
  • Do you need to perform maintenance of IT devices, run GUI applications, troubleshoot and remotely reboot hardware?
  • Do you need to manage mission-critical servers and give direct access to multiple remote users?

If you are wondering which KVM Switch you need, and what is the best KVM Switch to buy for your configuration, visit our KVM Swiches and Extenders page. Find recommendations, suggestions and all the important features you should look for when purchasing a KVM Switch