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Keyboard latency

danluu.com

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Re: Keyboard latency

#11

Post by Nition »

korethr wrote: post #2

IMO, 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…

I wouldn't be surprised if the Apple keyboard is the fastest just because it has very shallow keys.

Re: Keyboard latency

#12

Post by Heliosmaster »

Nition wrote: post #11
korethr wrote: post #2

IMO, 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…

I wouldn't be surprised if the Apple keyboard is the fastest just because it has very shallow keys.

They mentioned it being a likely culprit in the article :)

Re: Keyboard latency

#13

Post by Nition »

Heliosmaster wrote: post #12
Nition wrote: post #11

Earlier quoted context omitted.

I wouldn't be surprised if the Apple keyboard is the fastest just because it has very shallow keys.

They mentioned it being a likely culprit in the article :)

Oops, yeah I just got to that part. My fault for not reading past the conclusion before posting.

Still, I guess in a way, timing it from the start of a key press is the most real measure of actual latency when you want to press a key. It's just got nothing to do with the processor etc.

Re: Keyboard latency

#14

Post by HugoDaniel »

matthavener wrote: post #3

PS/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...

do serious gamers avoid v-sync ? even at 120Hz they get at least ~8ms * 2(double buffer) latency right ?

Re: Keyboard latency

#15

Post by dsr_ »

HugoDaniel wrote: post #14
matthavener wrote: post #3

PS/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...

do serious gamers avoid v-sync ? even at 120Hz they get at least ~8ms * 2(double buffer) latency right ?

Yes, they want freesync or g-sync monitors with high refresh rates.

Re: Keyboard latency

#16

Post by AmVess »

colanderman wrote: post #9

I'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…

Yes, and something like a touch interface is very obvious, too.

Look at this video on Youtube from Microsoft Applied Sciences Group: High Performance Touch.

https://www.youtube.com/watch?v=vOvQCPLkPt4

You can plainly see that 100ms is an eternity. While keyboards aren't the same thing, but high latency is noticeable. I had to change a keyboard because of the near eternity of when I pressed a key and when it registered on the screen. The difference between the old and the new is quite stark.

Re: Keyboard latency

#17

Post by bastijn »

korethr wrote: post #2

IMO, 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…

Didn’t watch good enough. There are mechanical keyboards in the review as mentioned below. My bad. Original comment below for future reference.

—- original comment —-

True gaming keyboards have mechanical switches which activate on first key press, not on full key down. Bit disappointed no mechanical keyboard was tested as they are perceived to be the ultimate keyboards when speed matters.

Re: Keyboard latency

#18

Post by rubatuga »

theandrewbailey wrote: post #8
matthavener wrote: post #3

PS/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...

Saying that PS/2 boards are "scanned" is inaccurate, as they trigger an interrupt immediately on a keypress.

Doesn’t the micro controller in the keyboard still scan, and then send a ps/2 signal?

Re: Keyboard latency

#19

Post by dom0 »

bastijn wrote: post #17
korethr wrote: post #2

IMO, 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…

Didn’t watch good enough. There are mechanical keyboards in the review as mentioned below. My bad. Original comment below for future reference. —- original comment —- True gaming keyboards have mechanical switches which activate on first key press, not on full key down. Bit disappointed no mechanical keyboard was tested as they are perceived to be the ultimate keyboards when speed matters.

> which activate on first key press

No, mechanical keys have some travel before actuation as well.

Re: Keyboard latency

#20

Post by mhweaver »

bastijn wrote: post #17
korethr wrote: post #2

IMO, 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…

Didn’t watch good enough. There are mechanical keyboards in the review as mentioned below. My bad. Original comment below for future reference. —- original comment —- True gaming keyboards have mechanical switches which activate on first key press, not on full key down. Bit disappointed no mechanical keyboard was tested as they are perceived to be the ultimate keyboards when speed matters.

I see several mechanical keyboards in the list (das, ergodox, kinesis advantage, olkb planck, possibly others)
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