The Cherry MX Board 6.0 Mechanical Keyboard Reviewby E. Fylladitakis on January 27, 2016 8:00 AM EST
In order to test the quality and consistency of a keyboard, we are using a texture analyser that is programmed to measure and display the actuation force of the standard keyboard keys. By measuring the actuation force of every key, the quality and consistency of the keyboard can be quantified. It can also reveal design issues, such as the larger keys being far softer to press than the main keys of the keyboard. The actuation force is measured in Centinewton (cN). Some companies use another figure, gram-force (gf). The conversion formula is 1 cN = 1.02 gf (i.e. they are about the same). A high quality keyboard should be as consistent as possible, with an average actuation force as near to the manufacturer's specs as possible and a disparity of less than ±10%. Greater differences are likely to be perceptible by users.
The machine we use for our testing is accurate enough to provide readings with a resolution of 0.1 cN. For wider keys (e.g. Enter, Space Bar, etc.), the measurement is taking place at the center of the key, right above the switch. Note that large keys generally have a lower actuation force even if the actuation point is at the dead center of the key. This is natural, as the size and weight of the keycap reduces the required actuation force. For this reason, we do display the force required to actuate every key but we only use the results of the typical sized keys for our consistency calculations. Still, very low figures on medium sized keys, such as the Shift and Enter keys reveal design issues and can easily be perceptible by the user.
The quality testing of the Cherry MX Board 6.0 gave us unnaturally good results, smiting every other mechanical keyboard that we have tested to this date - including those made with Cherry's own switches. Our instruments recorded an average force of 43.5 cN, with a disparity of just ±1.61% for the main keys. Even the force of the larger keys is abnormally close to that of the smaller keys, as their force figures are usually significantly lower due to the size of the keycap.
Although this is just an assumption on our part, we believe that these abnormal figures are a product of more than just the lack of variability in Cherry's mechanical switches. Our testing equipment is set to hold the force value once a key has been actuated, but it can only realize that it has actually been actuated once the keyboard sends a signal to a computer. Inherently, this process has a latency of a few milliseconds, during which the analyzer keeps increasing the force. Cherry claims that with the Realkey technology of this keyboard, it can signal the system every single millisecond. Again, this is a mere educational guess on our part, but it may be that Cherry effectively minimized the latency of the keyboard, which is now signaling our test system to stop more consistently. This could explain the abnormal consistency of the results, as a latency of even a few ms would increase every recorded value slightly.