I've been wondering about this for longer than I care to admit. I always felt the perceived responsiveness of my old sparc 20 was much better than pcs I used 15 years later, and I thought it had to do with keyboard latency and interrupt processing.
Keyboard latency
61–70 of 274 posts
Re: Keyboard latency
#62Re: Keyboard latency
#63Earlier quoted context omitted.
That's fine though. It's about the experience end-to-end. I love the apple keyboards. I still type faster on them than other keyboards, including high-end mechanical keyboards. The short keys and actuation feel responsive, yet I've never felt like I've accidentally triggered a key.
Agreed, and I don't understand the hate many people (seem to) have for them - the most ergonomic keyboards are those that require the least amount of repetitive motion. Not that there isn't an adjustment period, but some seem to pull out their Jump To Conclusion mats a little early.
There's essentially no range of motion in a MBP keyboard anymore: there is no difference between not pressing the key, actuating the key, and bottoming out the key. Some people (such as yourself) seem to prefer it, but to me it feels much rougher than comparable keyboards, like typing on a hard plastic surface. There is no give or play in the keystroke. Compared to a Lenovo T460p's keyboard (the other machine I own), the Lenovo is a lot "softer" to type on. (And quieter, too.) Mostly, I dislike the feel.
Now, my wrists also hurt. Now, when I'm not travelling, I was using an external Apple keyboard, not the MBP's primarily, so I'm hesitant to blame the MBP's keyboard directly. The external Apple keyboard has a greater keystroke distance from start to bottoming out, but still has like zero distance between actuation and bottoming out. (For some keystrokes, particularly ^+Tab and ^+Shift+Tab, I find it hard to keep control actuated, despite it being fully depressed; it just seems to require a lot of pressure to keep things in electrical contact). The pain in my wrists didn't start until I started using Apple keyboards, and has mostly stopped since I've replaced them. (I now primarily use an ErgoDox EZ, primarily for the split/ability to independently position my hands. I had tried, and had similar success w/ a Kinesis Freestyle, but I didn't own it.)
(I used a MBP keyboard for ~4yrs, with an ergo keyboard of some kind for when I'm not travelling for ~half of that. I've used Thinkpad's of varying models for ~10 years. Now, I could just be getting old, but replacing the Apple keyboard is what made the difference thus far for me. It doesn't make a lot of sense to me, admittedly: my wrists are, I feel, in the same bad position on the Lenovo as they are on the MBP/Apple keyboard.)
Re: Keyboard latency
#64Measuring using sound should be more precise. Even a bad mic has orders of magnitude more time resolution than a 240fps camera.
Something like click-to-beep.
Re: Keyboard latency
#65I find my typing accuracy is affected by keyboard latency.
An interesting way to test this would be to use a sensor to note how the point where a key was definitely "headed down" (say > 10% of its total travel) and then waiting for the message to show up.
In older keyboards the main CPU was doing some of the debouncing so it knew "right away" that a keyboard was pressed. That cuts down on latency as well.
Another test case might be to put a USB -> PS/2 adapter on the keyboard. This lets the onboard CPU know to send the keycode as soon as it has decoded and debounced it.
Re: Keyboard latency
#66IMO, a better measure would be from activation of the switch, as opposed to the beginning of key travel. I don't start waiting for the character to appear on my screen from the moment I begin to press down. My anticipation begins when I feel the tactile feedback of the switch activating (or the switch bottoming out on switches that don't offer tactile feedback). On a keyboard with good tactile feedback, I might not m…
A weird result with the Das 3 keyboard (25ms) considering it uses a cherry MX switch, same as the Kinesis (55ms).
The OLKB and Ergodox don't state the switches used, but it's almost certainly a cherry MX style switch with non-modified actuation points compared to the original.
Re: Keyboard latency
#67[deleted]
Re: Keyboard latency
#68Earlier quoted context omitted.
That's fine though. It's about the experience end-to-end. I love the apple keyboards. I still type faster on them than other keyboards, including high-end mechanical keyboards. The short keys and actuation feel responsive, yet I've never felt like I've accidentally triggered a key.
I'm currently using a mechanical 60% keyboard with the following layout: http://www.keyboard-layout-editor.com/#/gists/c7f9f0ac904b21... Truth be told, I also prefer scissor switch keyboards, but there aren't any on the market that support the features I'd like: - configurable keys & layers on a hardware level - 60% layout - NKRO Apple's magic keyboard would be great if it supported configuration/NKRO and didn't cost…
Custom build at wasd keyboards work? I love that place.
Re: Keyboard latency
#69I'm surprised the "humans don't notice 100 ms" argument is even made. That's trivially debunkable with a simple blind A/B test at the command line using `sleep 0.1` with and without `sleep` aliased to `true`. To my eyes, the delay is obvious at 100 ms, noticeable at 50 ms, barely perceptible at 20 ms, and unnoticeable at 10 ms. Not to mention that 100 ms is musically a 16th note at 150 bpm. Being off by a 16th note e…
This rule comes from UX design user studies. However, the actual rule is that people perceive an event happening within 100ms as "instantaneous". Or, in other words, two events happening within 100ms of each other won't feel like distinct events. This doesn't mean that users won't notice the delay and it doesn't even mean users won't be frustrated by it, it's just a matter of human perception of distinct events in time.
Unfortunately, programmers/UX designers have a tendency to generalize this rule and use it to excuse slow user interfaces.
Re: Keyboard latency
#70PS/2 keyboards are used by serious gamers because the scan rate is higher than USB. See https://superuser.com/questions/16893/do-usb-or-ps-2-keyboar...
Isn't PS/2 interrupt based? So there would be no scan rate. Haven't looked at your link though.
There are two "scan" rates: the rate at whitch keyboard matrix is scanned by whatever electronics is inside keyboard (that is probably independent of the outside interface) and the rate at which the interface is able to process input events, which for PS/2 means faster that the keyboard can produce them (as keyboard is essentially bus master on the AT/PS2 keyboard "bus") and for USB means as fast as the *HCI pools keyboard for interrupt events (old Apple's ADB works the same way and is in fact to some extent inspiration for USB Edit: then there is third approach: simple keyboard/input devices with serial interfaces, where host provided clock is used to both clock the interface and keyboard scan logic. In essence the whole keyboard then looks like one big shift register. Keyboards that works this way includes original Macintosh, most Wyse and DEC terminals and MIT/LMI/Symbolics Lisp machines (and probably pre-sun4 Suns, sun4 and later have rs232-derived ionterface), also this is the way how controllers for Nintendo consoles before Wii work (IIRC Nintendo calls that "EXI bus") and how PlayStation 1/2 controllers work. IMHO this is to some extent where the idea behind SPI comes from.