5 ms·

A really good typist runs around 100 words per minute. 30 millisceonds of delay vs 2 is enough that the terminal won't keep up with the person working on it.

A really good typist runs around 100 words per minute. 30 millisceonds of delay vs 2 is enough that the terminal won't keep up with the person working on it. And these are TERMINALS, other software has gotten much worse in typing latency.

PragmaticPulp 6y ago
I think you’ve misinterpreted these results. The delays don’t mean that the terminal will start missing keys or won’t keep up with the operator. Humans don’t type on a tight feedback loop of waiting for characters to pop up on the screen, obviously. We also need to keep the big picture in mind. If you’re using a 60Hz monitor, it’s only going to update every 17ms anyway. Add buffering and even pixel transition latency to the equation and the end-to-end latencies are even higher. You’re not going to notice the difference between a terminal editor with 20ms of latency and one with 15ms of latency.
- 65536 6y ago
  I have definitely used software where it started lagging behind significantly while I was typing. That kind of stuff is absolutely infuriating.
  - PragmaticPulp 6y ago
    That’s a very different problem than the 15-30ms latency discussed in the link above.
- formerly_proven 6y ago
  Nah, I've written texts in certain Word editors and IDEs and looked up mid-paragraph for spellchecking or re-reading it, just to see the computer still spurting out letters on the screen slower than an half-asleep OM morsing it. Sometimes these multi-core 4+ GHz fast marvels of nanotechnology simply can't keep up with a meatbag on caffeine punching keys for food. Sad in a poetic way.
  - PragmaticPulp 6y ago
    That’s an entirely different issue. The original link discussed typing latencies in the range of 1-30ms. That’s a fraction of the blink of an eye. If your computer is so slow that it takes multiple seconds for letters to appear, something else is happening. Even old “fast” software is going to feel laggy if your system is so bogged down that it can’t keep up with typing inputs on that level.
    - Junk_Collector 6y ago
      I'm taking issue with latency in general and it's dismissal. There are reams of ergonomic targets, data, and guides on user interface latency that are just completely ignored these days. A terminal is close to the simplest possible interface whose job is to provide input and output to a user with as little disruption as possible. 30 ms is in fact noticeable. Here is a short video from Microsoft (about 10 years old now) on the experience of using a touchscreen with 100ms of delay vs 1ms showing the steps in between. The difference is extraordinary for the user even if the end result is the same. https://www.youtube.com/watch?v=vOvQCPLkPt4 https://www.youtube.com/watch?v=vOvQCPLkPt4
      - PragmaticPulp 6y ago
        > Here is a short video from Microsoft (about 10 years old now) on the experience of using a touchscreen with 100ms of delay vs 1ms showing the steps in between. The difference is extraordinary for the user even if the end result is the same. That’s additional input delay, not absolute latency. More importantly, the visual effect you’re seeing isn’t the perception of input delay. It’s the positional difference between the finger location and the box location. Typing in a terminal doesn’t have the same visual difference. In fact, using a mouse doesn’t have the same visual difference because your finger isn’t right next to the screen for comparison. Try dragging a window across your screen right now. The “lag” is easily on the order of the 100ms shown in this demo, but you won’t find it anywhere near as disorienting because your finger isn’t on the screen for visual reference. It’s not possible to have 1ms lag unless you have a 1000Hz screen and zero processing time for the inputs. Compare that to the standard 60Hz displays that most laptops and cellular phones use. At 60Hz, the screen only updates once every 17ms. Add input lag, processing lag, rendering delay, buffering delay, and other delays and it’s nearly impossible to go from input to screen action in under 30ms. Most games are on the order of 60-80ms. The individual pixels in your LCD can’t even toggle from black to white in 1ms. A lot of the HN comments here are misunderstanding the time scales involved in all of this. For reference, a blink of an eye is about 100ms
- kqr 6y ago
  > Humans don’t type on a tight feedback loop of waiting for characters to pop up on the screen, obviously. Actually, yes, they do. I can't dig up the reference right now, but evidence indicates that for touch typists, error rates rise as input latency increases. Apparently, seeing your characters appear on screen is a cue the brain uses together with mechanical feedback and other things to do small muscular corrections on the fly. So there's nothing obvious about a claim to the contrary.
  - PragmaticPulp 6y ago
    > Actually, yes, they do. I can't dig up the reference right now, but evidence indicates that for touch typists, error rates rise as input latency increases On what magnitude, though? Can you please share the actual paper? My claim was that 15ms vs 20ms input latency (actual numbers from the parent comment’s link) won’t make a difference. That shouldn’t be controversial, because all of our standard 60Hz monitors only refresh the frame every 17ms anyway. For reference, blinking your eyes takes about 100ms. The difference between 15ms and 20ms latency is only 5ms, or literally 1/20th of the blink of an eye. That difference isn’t going to change your typing error rate. 1 second of input latency will, but that’s orders of magnitude higher than anything discussed here.
onion2k 6y ago
No one is typing 100WPM in a terminal though. If you're writing a document use a word processor that's optimised for input speed more than your terminal app, or use a faster terminal app with fewer features that slow it down. Leave the terminal apps that can only handle 50WPM alone so the rest of us can have the useful stuff.
- userbinator 6y ago
  I can type prose at ~150WPM pretty much continuously, with bursts of 200+ in short phrases. I have never measured how fast I type in a terminal, but it's definitely far more bursty, and that's when lag becomes far more unacceptable.
- markstos 6y ago
  I prefer Vim for writing. Plenty of writers prefer text editors to word processors for writing. No need to be either/or. Fast AND useful is possible.
- adrianN 6y ago
  Are you saying that Microsoft Word has a lower latency than Emacs in a terminal?

PragmaticPulp 6y ago

I think you’ve misinterpreted these results. The delays don’t mean that the terminal will start missing keys or won’t keep up with the operator. Humans don’t type on a tight feedback loop of waiting for characters to pop up on the screen, obviously. We also need to keep the big picture in mind. If you’re using a 60Hz monitor, it’s only going to update every 17ms anyway. Add buffering and even pixel transition latency to the equation and the end-to-end latencies are even higher. You’re not going to notice the difference between a terminal editor with 20ms of latency and one with 15ms of latency.

65536 6y ago
I have definitely used software where it started lagging behind significantly while I was typing. That kind of stuff is absolutely infuriating.
- PragmaticPulp 6y ago
  That’s a very different problem than the 15-30ms latency discussed in the link above.
formerly_proven 6y ago
Nah, I've written texts in certain Word editors and IDEs and looked up mid-paragraph for spellchecking or re-reading it, just to see the computer still spurting out letters on the screen slower than an half-asleep OM morsing it. Sometimes these multi-core 4+ GHz fast marvels of nanotechnology simply can't keep up with a meatbag on caffeine punching keys for food. Sad in a poetic way.
- PragmaticPulp 6y ago
  That’s an entirely different issue. The original link discussed typing latencies in the range of 1-30ms. That’s a fraction of the blink of an eye. If your computer is so slow that it takes multiple seconds for letters to appear, something else is happening. Even old “fast” software is going to feel laggy if your system is so bogged down that it can’t keep up with typing inputs on that level.
  - Junk_Collector 6y ago
    I'm taking issue with latency in general and it's dismissal. There are reams of ergonomic targets, data, and guides on user interface latency that are just completely ignored these days. A terminal is close to the simplest possible interface whose job is to provide input and output to a user with as little disruption as possible. 30 ms is in fact noticeable. Here is a short video from Microsoft (about 10 years old now) on the experience of using a touchscreen with 100ms of delay vs 1ms showing the steps in between. The difference is extraordinary for the user even if the end result is the same. https://www.youtube.com/watch?v=vOvQCPLkPt4 https://www.youtube.com/watch?v=vOvQCPLkPt4
    - PragmaticPulp 6y ago
      > Here is a short video from Microsoft (about 10 years old now) on the experience of using a touchscreen with 100ms of delay vs 1ms showing the steps in between. The difference is extraordinary for the user even if the end result is the same. That’s additional input delay, not absolute latency. More importantly, the visual effect you’re seeing isn’t the perception of input delay. It’s the positional difference between the finger location and the box location. Typing in a terminal doesn’t have the same visual difference. In fact, using a mouse doesn’t have the same visual difference because your finger isn’t right next to the screen for comparison. Try dragging a window across your screen right now. The “lag” is easily on the order of the 100ms shown in this demo, but you won’t find it anywhere near as disorienting because your finger isn’t on the screen for visual reference. It’s not possible to have 1ms lag unless you have a 1000Hz screen and zero processing time for the inputs. Compare that to the standard 60Hz displays that most laptops and cellular phones use. At 60Hz, the screen only updates once every 17ms. Add input lag, processing lag, rendering delay, buffering delay, and other delays and it’s nearly impossible to go from input to screen action in under 30ms. Most games are on the order of 60-80ms. The individual pixels in your LCD can’t even toggle from black to white in 1ms. A lot of the HN comments here are misunderstanding the time scales involved in all of this. For reference, a blink of an eye is about 100ms
kqr 6y ago
> Humans don’t type on a tight feedback loop of waiting for characters to pop up on the screen, obviously. Actually, yes, they do. I can't dig up the reference right now, but evidence indicates that for touch typists, error rates rise as input latency increases. Apparently, seeing your characters appear on screen is a cue the brain uses together with mechanical feedback and other things to do small muscular corrections on the fly. So there's nothing obvious about a claim to the contrary.
- PragmaticPulp 6y ago
  > Actually, yes, they do. I can't dig up the reference right now, but evidence indicates that for touch typists, error rates rise as input latency increases On what magnitude, though? Can you please share the actual paper? My claim was that 15ms vs 20ms input latency (actual numbers from the parent comment’s link) won’t make a difference. That shouldn’t be controversial, because all of our standard 60Hz monitors only refresh the frame every 17ms anyway. For reference, blinking your eyes takes about 100ms. The difference between 15ms and 20ms latency is only 5ms, or literally 1/20th of the blink of an eye. That difference isn’t going to change your typing error rate. 1 second of input latency will, but that’s orders of magnitude higher than anything discussed here.

onion2k 6y ago

No one is typing 100WPM in a terminal though. If you're writing a document use a word processor that's optimised for input speed more than your terminal app, or use a faster terminal app with fewer features that slow it down. Leave the terminal apps that can only handle 50WPM alone so the rest of us can have the useful stuff.

userbinator 6y ago
I can type prose at ~150WPM pretty much continuously, with bursts of 200+ in short phrases. I have never measured how fast I type in a terminal, but it's definitely far more bursty, and that's when lag becomes far more unacceptable.
markstos 6y ago
I prefer Vim for writing. Plenty of writers prefer text editors to word processors for writing. No need to be either/or. Fast AND useful is possible.
adrianN 6y ago
Are you saying that Microsoft Word has a lower latency than Emacs in a terminal?