On the surface, all keyboards look pretty much the same. Most users when choosing a keyboard, look mainly at the layout, whether there is a separate numeric keypad for quick numerical entry, and the letter ordering. The standard layout for English language keyboards is the QWERTY, which is derived from the order of the first six letters located at the top left.
However, there’s a lot more to choosing a keyboard than just the layout, which can make a world of difference depending on the requirements of the user. A secretary will have different needs from a programmer, and both would have different needs from a gamer.
The first keyboards were originally designed for typewriters in the 1870s, over a century before the first personal computers appeared. These early keyboards used long, mechanical levers with a very distinct action. Today’s computer keyboards use a number of switch technologies, such as membrane, dome-switch, scissor-switch (found in use on most laptop keyboards), and even optical. However, the most common technology found on desktop keyboards is the mechanical switch.
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Mechanical Switch Technology Explained
Today, the major producer of mechanical switches used in computer keyboards is Cherry GMBH, based in Germany (although the company was originally founded in the United States in the early 1950s). The Cherry MX series, introduced in 1985, is the company’s most popular line of switches, and are classified according to their physical color.
Color classification helps identify switch characteristics, such as operating force, pre-travel, total travel, audible feedback, and whether the switch is linear or offers tactile feedback. It is these characteristics that makes each switch either more, or less suitable for a particular use. For example, an audible click with each keypress may be necessary in some uses, but could be annoying for anyone doing a lot of continuous typing.
A switch’s operating force, expressed in centi-Newtons or cN, is how much downward force must be applied to operate the switch. The greater the numerical value, the more downward force required. The operating force is achieved through the use of a coiled compression spring.
The stiffer the spring, the greater the resistance offered and the greater the opposing force created. This means, switches with a higher cN value, are harder to press, but also rebound much faster. For users who do a lot of typing, keyboards with switches that have a high cN value, can create fatigue of the fingers.
The actuation point is the depth to which a key must be pressed before it registers the keystroke and sends it to the connected device, usually a computer system.
Pre-travel is the distance a switch must be pressed from the point of rest, before it actuates or reaches its operating position. It is usually about half the total travel distance. Total travel, sometimes also referred to as full travel, is the distance from the point of rest to the point where the switch bottoms out.
While switch actuation occurs at the limit of pre-travel as the key is depressed, switch reset (also referred to as release or break point) occurs slightly closer to the switch’s rest point as the key is being released. If for example, switch actuation occurs at a depth of 2.2mm from the rest point, reset would typically occur slightly higher at 2.0mm from the rest point. This difference is known as hysteresis.
Audible feedback refers to a clicking sound generated when the switch registers a keypress. While not all switches provide audible feedback, in some cases it helps to have this audible confirmation that the keypress has registered.
Finally, linear and tactile feedback refer to whether the entire journey from rest to total travel is smooth and constant, or if there is a discernible bump at the point of actuation. In the first case, the only perceptible indication that the key has registered, is when the switch hits bottom.
With tactile feedback, a bump is felt when the keypress has registered and there is no need to continue downward pressure until bottoming out. This results in less distance traveled and therefore less fatigue, and also since the switch does not impact when hitting bottom, increases switch lifetime.
The following table lists the different Cherry switches and their respective characteristics.
Switch | Linear / Tactile | Operating Force (cN) | Pre-travel (mm) | Total Travel (mm) | Audible Feedback |
|---|---|---|---|---|---|
MX Red | Linear | 45 | 2.0 | 4.0 | None |
MX Brown | Tactile | 55 | 2.0 | 4.0 | None |
MX Blue | Tactile | 60 | 2.2 | 4.0 | Click at 4.0 total travel |
MX Black | Linear | 60 | 2.0 | 4.0 | None |
MX Silver Speed | Linear | 45 | 1.2 | 3.4 | None |
MX Green | Tactile | 80 | 2.2 | 4.0 | Click |
So, which switch is most suitable?
The MX Red switch was first introduced in 2008, and provides a smooth and direct response, which is why it has been popular with gamers, as well as with ordinary users.
There’s no (annoying for some) audible click, but with one of the lowest operating forces of any mechanical switch (at 45cN, giving the key a light touch), and no tactile feedback to slow down keystrokes, this switch allows the user to make quick and repetitive keystrokes, ideal for games requiring rapid fire or movement.
Cherry also has a MX Silver Speed switch which is almost identical to the MX Red switch, but with much smaller pre-travel (1.2mm vs 2.0mm) and total travel (3.4mm vs 4.0mm) distances. Although these differences are very small, they make for even faster keystrokes.
The MX Brown switch, introduced in 1994, is well suited to those requiring greater accuracy with their typing. It is still a very good switch for gaming, but the MX brown switch includes tactile feedback and requires slightly greater operating force than the MX Red switch.
The tactile feedback offers an added confirmation of keypress registration, and once the fingers have become used to sensing for the distinctive bump, the keystroke doesn’t have to travel all the way down until bottoming out.
The MX Blue switch, introduced in 2007, is very popular with some typists due to the fact that the switch has an audible click with every keypress (reminiscent of the older mechanical typewriters) and tactile feedback. This switch has a higher operating force of 60cN, which makes it a heavier switch.
Although not ideal for shooter games where rapid fire is required, they are popular with players of real-time strategy games which require accuracy rather than speed. Many top game keyboards offer the MX Blue switch alongside the MX Red and MX Brown switches.
Conclusion
Unlike so many components on a computer system, where the specifications, such as capacity, read and write speeds, dictate which hard disk or solid state drive is better, selecting a keyboard is far more personal choice. After all, you plug in a disk drive and then forget about it, but you are physically connected to a keyboard while using it continually, and it just has to feel right.
Some users like a light, responsive, no frills touch, others require some kind of audible or tactile feedback, reassuring them of each keypress. And while a programmer has different needs from a typist, we find that even within the same realm, one gamer may have different requirements from another gamer. There’s no such thing as one size fits all.
Fortunately, there is a wide range of mechanical switches to choose from and many keyboard manufacturers offer a choice of switch when selecting a keyboard. And even though we’ve looked at the most common, in the MX Red, MX Brown, and MX Blue switches, there are several others available from Cherry, as well as other keyboard switch manufacturers, that are sure to fit any requirement.
The MX Red switch is a good, smooth, fast, direct action multi-purpose switch. If you prefer to feel what you type, then the MX Brown switch, with its tactile feedback, may be the switch for you. And for an even greater sensory bond, the MX Blue switch with tactile feedback, audible click and firmer touch is available.
Finally, while there are other keyboard technologies available, such as membrane or dome switch, the mechanical switch has proved to be a very reliable and long lasting keyboard switch, able to take the toughest beating.