I read of gamers specifically using PS/2 keyboards. Specifically I’m thinking of someone playing Esport games on 144 Hz monitors.
This is NOT how a USB keyboard should be attached to any OS, and it hasn't been for at least a decade. Modern OSes have native keyboard drivers which integrate USB keyboards like any other USB device and speak to them directly, thereby bypassing that BIOS logic that introduces the delay. Such a driver is then capable of receiving key input with the delay depending on the USB bus delay. That is way shorter than 16ms, but also kind of hard to determine, because with USB being a host-controlled and shared interface, it basically depends on a) whether there is any other device also communicating and b) on the rate by which the host polls the device for new data. As far as I know, the latter is configurable (by the device and/or the driver, I'm unsure about that) within certain intervals, and it is possible to poll a keyboard at 1000Hz or even faster, so we're back at a theoretical delay of about 1ms - however, this time that's for the entire byte sequence belonging to a key press/release, not just for one byte as with the PS/2 keyboard, so this delay can directly be translated to keys pressed - no scancode sequences of differing length to account for.
The biggest latency is the time it takes for the keyboards own SOC to recognize the press with mechanical keyboards there can also be additional latency for things like debouncing depending on the switch in question.
Overall the best keyboard you can use today is one with a low latency controller and 1000hz polling rate it will be about 2-3 times “faster” than a PS/2 keyboard.
...shows that the keyboard latency is actually a significant part of input lag.
Debouncing isn't limited to keyboards this is a concept in electronic switching.
The method of debouncing (software, hardware or both) as well as the "debounce" window which can be set beyond a certain base limit to an arbitrary value has an impact on latency.
"Gaming" keyboards that tend to push the limit of what is acceptable for debouncing like the first generation Razer ones have had issues with keys registering multiple times for a single press.
Most current keyboards don't use the first "drop" as a keypress and usually count 2-3 drops depending on the switch type, and then also have their window set for key repeat if the key is still pressed which then adds additional latency.
Heck even with "normal" keyboards you can sometimes see this in action while keeping a key pressed you might notice that the repeat typing is sometimes jittery that is usually the debouncing in action.
The reason why mechanical switches can be worse off than membrane is because of how the electrical contact is made.
Benchmarking the time from switch activation to the computer being aware of the input should be doable (i.e. ignoring display latency and most of the software stack), alas no tech reviewers I know of do it. So no easy way for a consumer to compare products. IIRC someone measured the Wooting One to have ~4ms of latency. It does have a switch with adjustable actuation point (not so useful if you get the clicky version, since you cant adjust the tactile bump and click).
Edit: By high actuation point I mean farther from the board, it's usually specified from the start of the key travel, so lower numbers.
Probably had to do with old arcade games being deterministic and coded in assembly, as well as the vector display.
NKRO couldn't matter less.
So it might be only 2KRO, depending on which keys you're pressing. Just unlucky if those keys happen to be "W" and "A".
People started playing fps with the big keypad, but you'd often run into issues where you could only use 2 or 3 keys at a time.
Several games such as Duke Nukem etc came with utilities in which you could check if your specific keys would lock the keyboard; after that the default movement keys switched to wasd. For myself I preferred to use 1 finger per key, so I switched to escf.
I do know that I had to tweak MS Office apps in the Logitech G software because dragging an Excel window recalculates rows on window drag and the refresh rate of my mouse was so high that it caused noticeable lag, I'm confident it's easily hitting at most a few ms over wireless usb.
I get that the rhythmic nature of music enables precision at the scale of a few ms because musicians can anticipate these moments in time (reaction time does not apply). But I'm baffled by claims of sensitivity to delays less than about 10ms because these are near or even over the limits of acoustics. For example, when you do the math, you'll see that it is basically impossible for a large enough orchestra to play perfectly in sync. But a good orchestra can give the impression of a precise performance despite that. This can only mean that the human hearing is less precise than what people claim.
I think it's more like an "equivalent time sampling" effect, and the perceived 1ms latency is actually a perceived phase shift.
What you can hear are changes in latency which get added to the constant time the signal travels to the brain.
With some training I could achieve >95% confidence in discernig 5ms with my headphones.
Age impacts the frequency range that most people can hear. That might be a factor here too. I'm in my mid 30s, are you younger?
It screwed me up so much from the delay that I had to take my headphones off when recording otherwise I couldn't put together a sentence.
This claims that for percussionists 20ms is too much but 10ms is not. As a bassist I disagree, and think under 5ms is acceptable.
Because tween gamers could totally tell when the lag gets above 10ms. Which is all well and good but 12 year old boys start throwing the game controller when that happens, which causes higher failure rates. Which means more warranty returns.
1. Your brain wants to move a muscle
2. The muscle moves
3. The effect of the move is processed by your brain
This is of course only true if there are no reference points with lower latency. E.g. if you drag an item across a smartphone, we notice tiny latencies, because our finger moves before the icon – something we can easily see.
It isn't about training and practice. There is just a physical limitation of being a human.
However, when given samples of audio with no delay and a 5ms delay. I, with no special talent and no musical training, was able to start accurately identifying the delayed audio almost every time after a few minutes of practice.
The difference isn't imperceptible when it comes to a single noise when we are specifically told to look for it, but I would bet that its imperceptible when it comes to just randomly listening to music.
PS/2 does, but of course not all keyboards can deliver n-key even over PS/2.
The very same keyboards provide n-key if you use the USB->PS/2 adaptor in the box with the keyboard.
If it were straightforward there wouldn't be hacks such as pretending there's 2 keyboards in the system.
The problem with PS/2 is that most motherboards today don’t have it anymore so you can’t use passthrough adapters.
About two thirds of all current motherboards have PS/2.
Also the last gaming keyboard which still had native PS/2 support was the old non-macro enabled CM quickfire.
Despite Ryzen AMD is still negligible as far as market share goes.
edit: Also they do have a Z370 board with PS/2, the ROG STRIX Z370-G GAMING.
It looks like you got the only mono from Asus that comes with a PS/2 port other than the Apex: https://www.anandtech.com/show/11860/z370-motherboards-asus-...
https://geizhals.de/?cat=mbp4_1151v2&xf=317_Z370%7E7088_PS%2... (I don't know a similar English/US site)
I'm in Germany, could this site be blocking?