3 ms·

I'd argue that it's actually a good thing that the author ignored keyboard latency. We all have different keyboards plugged into different USB interfaces plugge

I'd argue that it's actually a good thing that the author ignored keyboard latency. We all have different keyboards plugged into different USB interfaces plugged into different computers running different versions of different operating systems. Throw hubs and KVMs into the mix, too. If the latency of those components varies wildly over the course of the test, it would introduce noise that reduces our ability to analyze the exact topic of the article - VTE's latency improvements. Even if the latency of those components were perfectly consistent over the course of the author's test, then it wouldn't affect the results of the test in absolute terms, and the conclusion wouldn't change. This exact situation is why differences in latency should never be expressed as percentages. There are several constants that can be normalized for a given sample set, but can't be normalized across an entire population of computer users. The author does a good job of avoiding that pitfall. The Mutter thing is interesting. The author holds that constant, and GNOME sits on top of Mutter, so I think it's reasonable to assume we'd see the same absolute improvement in latency. GNOME may also introduce its own undesirable variance, just like keyboard latency. I'd be very curious to see if those guesses holds up.

KronisLV 3y ago
> We all have different keyboards plugged into different USB interfaces plugged into different computers running different versions of different operating systems. I've actually been curious about getting a wireless keyboard recently, but wondered about how big of a latency impact there would be. Normally I use IDEs that definitely add a bit of sluggishness into the mix by themselves, but something compounded on top of that would probably make it way more annoying. A quick search lead me to this site: https://www.rtings.com/keyboard https://www.rtings.com/keyboard It does appear that they have a whole methodology for testing keyboards: https://www.rtings.com/keyboard/tests/latency https://www.rtings.com/keyboard/tests/latency For what it's worth, it seems that well made keyboards don't have too much latency to them, even when wireless (though the ones that use Bluetooth are noticeably worse): https://www.rtings.com/keyboard/1-3-1/graph/23182/single-key-latency-graph/razer-pro-type-ultra/29787 https://www.rtings.com/keyboard/1-3-1/graph/23182/single-key... Just found that interesting, felt like sharing. Might actually go for some wireless keyboard as my next one, if I find a good form factor. Unless that particular keyboard does something really well and most others just have way worse wireless hardware in them.
- Night_Thastus 3y ago
  If you get a modern wireless keyboard with 2.4 GHz wireless and use that instead of blutooth, the latency can be great - like you saw. Blutooth is still crap though, avoid that if you care about latency. Or reliable connections. Also be aware that despite being able, not all keyboards poll at 1KHz. My old wired keyboard polled at 66 Hz. My current wireless keyboard has a single-key latency around the 1.7 ms range. Better than many wired ones!
gsich 3y ago
Hubs have no noticable impact on latency. https://www.youtube.com/watch?v=nbu3ySrRNVc https://www.youtube.com/watch?v=nbu3ySrRNVc explains it and has some statistics.
- throwaway2037 3y ago
  To those who downvoted this comment, can you please explain why?

KronisLV 3y ago

> We all have different keyboards plugged into different USB interfaces plugged into different computers running different versions of different operating systems. I've actually been curious about getting a wireless keyboard recently, but wondered about how big of a latency impact there would be. Normally I use IDEs that definitely add a bit of sluggishness into the mix by themselves, but something compounded on top of that would probably make it way more annoying. A quick search lead me to this site: https://www.rtings.com/keyboard https://www.rtings.com/keyboard It does appear that they have a whole methodology for testing keyboards: https://www.rtings.com/keyboard/tests/latency https://www.rtings.com/keyboard/tests/latency For what it's worth, it seems that well made keyboards don't have too much latency to them, even when wireless (though the ones that use Bluetooth are noticeably worse): https://www.rtings.com/keyboard/1-3-1/graph/23182/single-key-latency-graph/razer-pro-type-ultra/29787 https://www.rtings.com/keyboard/1-3-1/graph/23182/single-key... Just found that interesting, felt like sharing. Might actually go for some wireless keyboard as my next one, if I find a good form factor. Unless that particular keyboard does something really well and most others just have way worse wireless hardware in them.

Night_Thastus 3y ago
If you get a modern wireless keyboard with 2.4 GHz wireless and use that instead of blutooth, the latency can be great - like you saw. Blutooth is still crap though, avoid that if you care about latency. Or reliable connections. Also be aware that despite being able, not all keyboards poll at 1KHz. My old wired keyboard polled at 66 Hz. My current wireless keyboard has a single-key latency around the 1.7 ms range. Better than many wired ones!

gsich 3y ago

Hubs have no noticable impact on latency. https://www.youtube.com/watch?v=nbu3ySrRNVc https://www.youtube.com/watch?v=nbu3ySrRNVc explains it and has some statistics.

throwaway2037 3y ago
To those who downvoted this comment, can you please explain why?