Hacker News Reader

Comment by lomlobon | Hacker News Reader

How's the latency? I've had to keep using xterm even though it kind of sucks just because it's got the lowest latency by quite a bit.

View on HN

According to this (at least 11 months old) benchmark, Ghostty has the worst input latency across all contenders: https://github.com/moktavizen/terminal-benchmark?tab=readme-...

More benchmarks from 4 months ago: https://news.ycombinator.com/item?id=45253927

14 months old discussion of input latency in Ghostty with comments from the author: https://github.com/ghostty-org/ghostty/discussions/4837

I don’t type more than 100 characters a second so I’ve never ran into bits limits.

If you're typing just one character per second you'll still feel the difference. Latency is stress inducing.

I'm generally very sensitive to input latency and there's no way Ghostty has 41ms. I've only been using it for a couple of months though, so I guess it's fixed now.

Edit: just saw your second link from 4 months and yes, it's now avg 13ms which feels about right to me. Not perfect but acceptable. So what's even the point of sharing the old benchmark?

The first link is a proper end-to-end benchmark with external camera (kudos to the author for making those), the second link is a more faulty software emulation

I have been using computers and terminal for a long time, and this kind of comment makes me think I must have missed a whole bunch of things which can be done with a terminal

Since people are mentioning latency I’ll mention throughput. Basically the idea is that you accidentally cat a large file to your terminal and we are measuring how much time it takes for the terminal to finish displaying it. This test generally favors GPU-accelerated terminals.

Ghostty performs very well on this regard, among the same league as Alacritty and Ptyxis.

Rather, what will win is a terminal that internally builds an efficient, symbolic representation of what is on the display, rather than a pixel representation with all the font glyph, and which efficiently sychronizes that symbolic representation to the graphical canvas, skipping intermediate updates when the abstract display is changing too fast.

That’s already happening I think. Newer terminals redraw at a fixed rate equal to the display refresh rate, usually 60Hz. But if there are more than 60 new characters being printed per second, some of these intermediate states are never rendered on screen.

It feels amazing on linux. I find it very noticably better than konsole.

Foot/Alacritty also feel amazing but they don't have some features of Ghostty.

My benchmark is opening neovim and scrolling with the mousewheel so not sure how represantative that is though

Have you tried kitty with more aggressive settings? It feels very responsive out of the box, but the defaults are balanced for sane energy use on portable machines.

  repaint_delay 5
  input_delay 1
  sync_to_monitor no

on my machine, noticeable. I seriously tried it, but went back because I could notice a small end-end latency, between keypress and action. But I'm also 240hz user.

Where are you measuring the keypress from? The nerve signal to your finger muscles?> Or the time the keycap hits bottom? What if the switch closes before the cap hits bottom: then we are getting a latency figure that looks better than it really is.

I've had a keyboard like that and with it, xterm (and nothing else) felt like it was displaying the characters even slightly before I had pressed them. It was a weird sensation (but good)

Nerve signals yes. I just try them side by side, usually running vim on both terminals and measuring how it feels. If you can feel difference, the latency is bad.

Reply on news.ycombinator.com