3 ms·

AFAIK you'd have to have a pretty bad keyboard for it to have a significant role in latency. I guess specialized hardware (based on a microcontroller with built

AFAIK you'd have to have a pretty bad keyboard for it to have a significant role in latency. I guess specialized hardware (based on a microcontroller with built-in USB host support) wouldn't be too hard to construct if you really needed to know. For the camera measurement, I would just press the key as fast as possible and pick about 3/4 of the way down as the trigger point.

jcelerier 5y ago
> AFAIK you'd have to have a pretty bad keyboard for it to have a significant role in latency https://danluu.com/keyboard-latency/ https://danluu.com/keyboard-latency/ puts a lot of keyboards >= 30 ms which is an insane amount of latency
- squeaky-clean 5y ago
  So if you check the appendix section, they say they're measuring latency not when the keyswitch makes contact, but when the finger first begins pressing on the key. So they're taking key travel time into account, and that ends up being the majority of the "latency". It's a fair point for the gaming argument they make, if you want to jump 30ms quicker you'll need shorter keys. But it's not really correct to say the keyboard is adding so much latency when it's actually the user.
  - jcelerier 5y ago
    > So if you check the appendix section, they say they're measuring latency not when the keyswitch makes contact, but when the finger first begins pressing on the key. So they're taking key travel time into account, and that ends up being the majority of the "latency". The key travel time on https://www.amazon.com/gp/product/B0000U1DJ2/ https://www.amazon.com/gp/product/B0000U1DJ2/ and https://www.amazon.com/gp/product/B00DGJALYW https://www.amazon.com/gp/product/B00DGJALYW is substantially the same, yet one has 20 ms of latency, and the other 55 ms.
wmwmwm 5y ago
I built one! Arduino Leonardo and a light dependent transistor: https://github.com/willmuldrew/lagmeter https://github.com/willmuldrew/lagmeter (It attempts to do a few other things but it’s best for measuring keyboard event to screen update latency)

jcelerier 5y ago

> AFAIK you'd have to have a pretty bad keyboard for it to have a significant role in latency https://danluu.com/keyboard-latency/ https://danluu.com/keyboard-latency/ puts a lot of keyboards >= 30 ms which is an insane amount of latency

squeaky-clean 5y ago
So if you check the appendix section, they say they're measuring latency not when the keyswitch makes contact, but when the finger first begins pressing on the key. So they're taking key travel time into account, and that ends up being the majority of the "latency". It's a fair point for the gaming argument they make, if you want to jump 30ms quicker you'll need shorter keys. But it's not really correct to say the keyboard is adding so much latency when it's actually the user.
- jcelerier 5y ago
  > So if you check the appendix section, they say they're measuring latency not when the keyswitch makes contact, but when the finger first begins pressing on the key. So they're taking key travel time into account, and that ends up being the majority of the "latency". The key travel time on https://www.amazon.com/gp/product/B0000U1DJ2/ https://www.amazon.com/gp/product/B0000U1DJ2/ and https://www.amazon.com/gp/product/B00DGJALYW https://www.amazon.com/gp/product/B00DGJALYW is substantially the same, yet one has 20 ms of latency, and the other 55 ms.

wmwmwm 5y ago

I built one! Arduino Leonardo and a light dependent transistor: https://github.com/willmuldrew/lagmeter https://github.com/willmuldrew/lagmeter (It attempts to do a few other things but it’s best for measuring keyboard event to screen update latency)