What Influences Keyboard Input Speed

Based on the title, I had hoped this article would be a study of fast typists to determine the most efficient typing styles. While this article is not that, if you also came to the comments looking for something like that, such studies do exist:

https://userinterfaces.aalto.fi/136Mkeystrokes/

An interesting conclusion is that "non-standard typists" are catching up to touch typists on standard keyboards. This matches my personal experience as someone whose teachers thought cursive would forever remain more relevant than typing...

https://www.sciencedaily.com/releases/2019/10/191002075925.h... https://news.vanderbilt.edu/2016/10/18/todays-self-taught-ty...

Some folks here might be familiar with QMK. I did a bit of tinkering with an Atmel-based split keyboard with a traditional matrix design (just like almost all custom mech keyboards).

My findings: the scan rate is around 200-2000hz (number of times a single key is checked per second). Having a split does lower this number, so does enabling i2c for either split communication or RGB.

I measured latency with an oscilloscope by checking the speed from having a key scan to a NumLock LED lighting up on the keyboard. It is variable, from 5ms all the way to 30.

I hear that ARM is way better in this regard. And ZMK might be better, too.

This is from 2018, with an update from 2019. It primarily focuses on the Wooting one, which is "sold out forever."

The key touted advantage of the Wooting one keyboard seems to be optical switches with an adjustable actuation point. It also uses a multiplexer for each row of keys, which is somehow faster than a scan matrix.

I don't see an actual test result for the keyboard that includes all of the latency factors discussed. The closest is a link to a tweet by Sunjun Kim. Unlike Dan Luu's measurements, which actually pressed a key, Sunjun triggered the optical switch using an LED, resulting in latency of 4.2 to 9.6 ms, depending on the firmware.

According to this post, key travel can add up to 10 ms, which the adjustable actuation is supposed to minimize. That would put the total latency at 10 to 15 ms, which is around what Dan Luu measured for Apple's Magic Keyboard.

This is a fantastic article, and a really good breakdown of how keyboards process inputs. Honestly though if 60ms is the worst that has been seen on modern keyboards (a wireless one, at that), then I'd say we're doing pretty good. 60ms is only ~5 frames of delay on a 60hz display, which means your input should register at frame 6 or 7, worst case scenario. That's honestly not bad, and still lower than a lot of wireless game controllers on the market (and some internet connections, for that matter).

> You know that argument that people used to have about 30 fps versus 60 fps? “The human eye can’t see the difference” and you don’t need more than 30 frames per second. By now you know better.

What a weird opener; if there's a topic that's plagued by anecdotal evidence it's this.