KVM Guide
KVM (Keyboard, Video and Mouse) Switches Explained

What is a KVM switch?

A KVM (Keyboard, Video & Mouse) switch allows you to control multiple computers from a single keyboard mouse and monitor. They are also known as CPU switches, server switches and PC switches.

Who needs to control multiple computers using a KVM switch?

Many organisations have multiple servers (for example, File/Web/Mail servers), which are only accessed infrequently. Using a KVM switch eliminates the need to waste money on a dedicated keyboard, monitor and mouse for each computer. This can also save valuable space and electricity.

KVM switch technology has many other situations including system builders, repair centers, ISPs, software developers and even home users with multiple computers.

Which KVM switch do I need?

From the features and explanations below it is quite easy to determine which are most essential to you. The "Products" section of our website helps you to narrow down your options by categorising the switches by number of users/computers.

• Computer Ports - Consider how many computers you need to control?
• Control Access Ports - How many access points do you need? Control from the server room and another office can be very useful!
• Simultaneous Control Access Ports (Number of users) - Similar to the above but allowing simultaneous computer access from more than one user
• CAT5 Control Access Ports - Incorporates hardware, which allows control over low cost cable at distances up to 200 metres. Additional hardware is required at the other end
• Platform (PC, Mac or Sun) - Depending on your computer systems. Some switches support mixed platforms
• Computer Keyboard/Mouse Interface Ports (PS/2, USB, Sun or RS-232) - Depending on your computers connectors
• Control Access Keyboard/Mouse Interface Ports (PS/2, USB or Sun) - Depending on the keyboard mouse you intend to use
• Video Interface (Analogue VGA or digital DVI) - VGA is commonly found used on most computers and monitors, however DVI is becoming more popular
• DDC2 "Plug & Play" Monitor Support - Allows the computers to determine the exact monitor connected, no need to manually configure
• Multimedia Support - Allows speakers and microphone to be connected and switched between computers
• Multihead Video Support - Allows computers which use multiple displays to be switched. Some models have built in support or can be expanded using the synchronisation port
• Maximum Video Resolution - Choose a model which supports the highest resolution which you will need to use
• Recommended Maximum Cable Distance - Consider the cable distances involved. Generally mains powered models allow longer cable distances than port powered models. Also see Power Method below
• Port Powered (Port Powered or Mains Powered) - Port powered switches do not need any additional mains socket whereas mains powered models generally allow for longer cable distances. Many port powered models also have the option to add a power supply, for extended distance or video only applications.
• Optional Redundant Mains Adaptor - Allows a second power supply to be added which prevents any down time in the event of a power supply failure
• Cascadable - Allows systems to be expanded by cascading switches together
• Switching Method (Keyboard, Mouse, Switch Button or Remote Control) - This is the method used to switch between connected computers. Keyboard switching is the most common, although other methods may be required depending on the situation.
• 19" Rackmountable - Do you want to install the KVM switch into a 19" server cabinet?
• Metal Housing - More robust and better suited to industrial applications.
• All Connectors on Rear - This allows cables to run neatly behind but the cost of the switch is generally higher
• On-Screen Display - This allows the switched to be configured and controlled using a simple on screen menu. Computers can be selected via user programmable names, avoiding the confusion.
• Security Password - Preventing unauthorised access
• Auto Scan - This allows the switch to scan between connected computers for easy monitoring
• Screen Saver - The screen can be blanked to prevent screen burning
• Flash Upgradeable - Allows for future firmware enhancements
• Warranty - All our KVM switches come with a 2 or 3 year Warranty as standard depending on the model