5 ms·

Just recently, I did a terminal latency test with Typometer for the following terminals, sorted by lowest latency: xterm (389-1) alacritty (0.13.1-1) ki

Just recently, I did a terminal latency test with Typometer for the following terminals, sorted by lowest latency: xterm (389-1) alacritty (0.13.1-1) kitty-tuned (0.31.0-1) zutty (0.14-2) st (master 95f22c5) urxvt (9.31-4) konsole (24.02.0-1) kitty (0.31.0-1) wezterm (20230712.072601) gnome-terminal (3.50.1-1) xfce4-terminal (1.1.1-2) terminator (2.1.3-3) tilix (1.9.6-3) hyper (v3.4.1) I only tested for software latency (monitor, keyboard and other hardware latency is not included in Typometer benchmarks). I ran the test on Arch Linux with Xorg + bswpwm without compositor. You can find the full results on by blog https://beuke.org/terminal-latency/ https://beuke.org/terminal-latency/.

kaba0 2y ago
Does it take into account Wayland, and its double-buffered nature (unless you specifically opt for disabling v-sync, see the presentation protocol)?
- Hendrikto 2y ago
  > I ran the test on Arch Linux with Xorg
  - kaba0 2y ago
    Missed that part, sorry. I thought one of those terminal emulators were Wayland only, hence my question.
- Jonnax 2y ago
  If the 16ms latency at 60hz bothers you. Then get a 120hz display which has 8ms latency. Or there's 240hz 4k displays with 4ms If that's not enough then there's 1080p esport monitors with 540hz so 1.85ms.
  - kaba0 2y ago
    It doesn’t bother me, I was just interested in whether the benchmark is fair in this respect (it is xorg only, so the answer is yes). I personally believe that 120+ hz gives barely any benefit, though.
snvzz 2y ago
>However, if we custom-tune the settings for the lowest latency possible I chose minlatency = 0 and maxlatency = 1 then we have a new winner. Applying this custom tuning results in an average latency of 5.2 ms, which is 0.1 ms lower than xterm, and that’s with having a much more sane terminal without legacy cruft. But... that max column. It hurts.
ykonstant 2y ago
What is kitty-tuned? Quick google didn't give useful info.
- sevg 2y ago
  The linked blog post has the details: > For kitty tuned I used the following settings: # 150 FPS repaint_delay 8 # Remove artificial input delay input_delay 0 # turn off vsync sync_to_monitor no Also, Kitty docs have some details here: https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-screen-latency https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-scr...
vagab0nd 2y ago
I use kitty. What's kitty-tuned?
- forgotpwd16 2y ago
  Kitty with settings in https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-screen-latency https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-scr....
deleted 2y ago
[deleted]
clktmr 2y ago
Very interesting! I would propose to add 'foot' to the list, which is also very performance oriented.
Vecr 2y ago
Huh, the devs really weren't lying, Alacritty really got better on the latency front. I started using it for supposed better security than Xterm, but at the time I think it was quite a lot worse on latency, but the throughput was way better.
aembleton 2y ago
Your blog post is from before Gnome 46 was released. It might be worth trying again to see if you see the improvements that the article describes.
forgotpwd16 2y ago
Compared to a similar 6yo [1] and 3yo[2] (by zutty maker) comparisons, VTE terminals still (at least pre-46) bad in latency front. (They're as high as VS Code based beuke article.) Xterm still rules it. (Pointed in [2], this is due to direct rendering via Xlib which comes with the downside of having poor throughput.) Alacritty significantly improved, Konsole got worse. About Alacritty, it's pointed in [2], there were various opened tickets related to its poor performance and wasn't an easy to solve problem. So kudos to Alacritty devs for succeeding and GNOME devs for improving in the new version. Alacritty, Kitty, Zutty, GNOME, others, quite a rejuvenation in terminal development. [1]: https://lwn.net/Articles/751763/ https://lwn.net/Articles/751763/ [2]: https://tomscii.sig7.se/2021/01/Typing-latency-of-Zutty https://tomscii.sig7.se/2021/01/Typing-latency-of-Zutty
christophilus 2y ago
I'd be curious how Foot holds up. In my subjective experience, it feels the least laggy when I use neovim.
SubiculumCode 2y ago
Here I was hoping that the Budgie default tilix was on the good end of this list. edit: More to the point though, is there much reason to go to kitty or alacrity?
- Xiol32 2y ago
  Finding it really hard to get off Tilix myself. Alacritty feels fast but they refuse to add support for tabs or tiling. They just say to go use tmux but that isn't the answer at all. Kitty is quite nice but if you SSH into machines a lot, all hell breaks loose if they don't have the kitty terminfo files installed, and doing that isn't always possible. You can override TERM, but honestly don't have the patience for it.

kaba0 2y ago

Does it take into account Wayland, and its double-buffered nature (unless you specifically opt for disabling v-sync, see the presentation protocol)?

Hendrikto 2y ago
> I ran the test on Arch Linux with Xorg
- kaba0 2y ago
  Missed that part, sorry. I thought one of those terminal emulators were Wayland only, hence my question.
Jonnax 2y ago
If the 16ms latency at 60hz bothers you. Then get a 120hz display which has 8ms latency. Or there's 240hz 4k displays with 4ms If that's not enough then there's 1080p esport monitors with 540hz so 1.85ms.
- kaba0 2y ago
  It doesn’t bother me, I was just interested in whether the benchmark is fair in this respect (it is xorg only, so the answer is yes). I personally believe that 120+ hz gives barely any benefit, though.

snvzz 2y ago

>However, if we custom-tune the settings for the lowest latency possible I chose minlatency = 0 and maxlatency = 1 then we have a new winner. Applying this custom tuning results in an average latency of 5.2 ms, which is 0.1 ms lower than xterm, and that’s with having a much more sane terminal without legacy cruft. But... that max column. It hurts.

ykonstant 2y ago

What is kitty-tuned? Quick google didn't give useful info.

sevg 2y ago
The linked blog post has the details: > For kitty tuned I used the following settings: # 150 FPS repaint_delay 8 # Remove artificial input delay input_delay 0 # turn off vsync sync_to_monitor no Also, Kitty docs have some details here: https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-screen-latency https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-scr...

vagab0nd 2y ago

I use kitty. What's kitty-tuned?

forgotpwd16 2y ago
Kitty with settings in https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-screen-latency https://sw.kovidgoyal.net/kitty/performance/#keyboard-to-scr....

deleted 2y ago

[deleted]

clktmr 2y ago

Very interesting! I would propose to add 'foot' to the list, which is also very performance oriented.

Vecr 2y ago

Huh, the devs really weren't lying, Alacritty really got better on the latency front. I started using it for supposed better security than Xterm, but at the time I think it was quite a lot worse on latency, but the throughput was way better.

aembleton 2y ago

Your blog post is from before Gnome 46 was released. It might be worth trying again to see if you see the improvements that the article describes.

forgotpwd16 2y ago

Compared to a similar 6yo [1] and 3yo[2] (by zutty maker) comparisons, VTE terminals still (at least pre-46) bad in latency front. (They're as high as VS Code based beuke article.) Xterm still rules it. (Pointed in [2], this is due to direct rendering via Xlib which comes with the downside of having poor throughput.) Alacritty significantly improved, Konsole got worse. About Alacritty, it's pointed in [2], there were various opened tickets related to its poor performance and wasn't an easy to solve problem. So kudos to Alacritty devs for succeeding and GNOME devs for improving in the new version. Alacritty, Kitty, Zutty, GNOME, others, quite a rejuvenation in terminal development. [1]: https://lwn.net/Articles/751763/ https://lwn.net/Articles/751763/ [2]: https://tomscii.sig7.se/2021/01/Typing-latency-of-Zutty https://tomscii.sig7.se/2021/01/Typing-latency-of-Zutty

christophilus 2y ago

I'd be curious how Foot holds up. In my subjective experience, it feels the least laggy when I use neovim.

SubiculumCode 2y ago

Here I was hoping that the Budgie default tilix was on the good end of this list. edit: More to the point though, is there much reason to go to kitty or alacrity?

Xiol32 2y ago
Finding it really hard to get off Tilix myself. Alacritty feels fast but they refuse to add support for tabs or tiling. They just say to go use tmux but that isn't the answer at all. Kitty is quite nice but if you SSH into machines a lot, all hell breaks loose if they don't have the kitty terminfo files installed, and doing that isn't always possible. You can override TERM, but honestly don't have the patience for it.