What are the most important elements to look for when buying KVM switches?
IT managers need to consider video type and resolution. What type of USB devices will by connected—HID devices such as keyboards and mice? If specialized keyboards are required, the KVM switch must be able to pass the proper emulation to CPUs. Another question to ask is whether you need audio, microphone and speakers.
The types of computers you would like to use with the KVM switch, and how they connect (DVI, VGA, PS/2, USB, audio, etc.) are important elements. Knowing the types of computers you plan on buying in the next five years helps you choose a switch to future-proof your investment. When looking at KVM switches, think about how many more computers/servers you plan on adding in the upcoming months and years. You don’t want to fully populate a KVM switch right away and discover you have to get the next size up or find a completely different solution. Also consider how far away the computers/servers/users will be from the centralized KVM switch. If any system/user will be farther than 15 feet, consider using a CATx-based solution where all computers/users will be interconnected via standard CAT5, CAT5e, or CAT6. Suppliers need to ask these questions to the end client to figure out what they really need and try to suggest options that would potentially save them money down the line.
What are the most common options available, and how do you decide which option is best?
Desktop KVM switches have the most common options. The market supports many systems from numerous manufacturers; however the switches do not all operate the same way. The most difficult thing to understand when looking at these types of switches is the difference in price between various four-port desktop switches. Prices can range from $60 all the way up to $450. When looking at these types of options and trying to compare the price difference, you will begin to notice major items that may not be immediately identified. Some of the major differences between these types of switches are the way video is supported, having a built-in EDID channel, or the ability to program your own channels. Programming your own EDID channel in a lower-end switch, you can easily encounter KVM switches that will not render the video correctly (e.g. shifted video, horizontal/vertical bars, no video/no signal, etc.). Between these two types of switches, you will also need to identify the type of USB operation the application requires. The $60 KVM switch may only support USB HID keyboards and mice, and if you try to plug in a USB flash drive, external storage device, or any other type of USB 2.0 device, it won’t function. On the other hand, the $450 KVM switch should offer the full USB spectrum functionality, and may even support true USB emulation.
See also the post on the three most common purchasing mistakes made when buying KVM switches.