Alacritty gets scrollback, publishes benchmarks

https://jwilm.io/blog/alacritty-lands-scrollback/

by jwilm • 8 years ago

62 34 8 years ago

jwilm.io

jwilm8• 8 years ago

Author here; I'm happy to answer any questions!

alakra• 8 years ago

Thanks for the updates! I'm compiling it now...

Y_Y• 8 years ago

How did you choose the terminals to benchmark against? What about xterm or gnome-terminal or powershell or whatever?

jwilm8• 8 years ago

We tried to strike a balance between "commonly accepted as fast" terminal emulators and coverage of "commonly used" terminal emulators. Termite gets us libvte-based terminals (like gnome-terminal), urxvt is generally considered as one of the fastest, and Kitty is another well-regarded GPU-accelerated terminal emulator. On macOS, there's not nearly as many choices.

Ultimately, it would be great if we could benchmark against every terminal emulator, but that can become a very time-consuming task. If there's another emulator you feel should be included, we can consider it for future updates/benchmarks.

matxip• 8 years ago

Not so much a question, but I wanted to thank you for the project. It's hit a sweet spot of configurability, stability, and performance for me, all without the baggage or caveats alternatives have. It's been my terminal of choice for a while now. Keep up the good work.

dreix• 8 years ago

Thank you very much. It's a delightful experience I have on all my machines.

lousken• 8 years ago

I hate the moment when I lose something in history so I've set my xfce4-terminal to 250k lines which was always enough so I've tried to set scrollback history to that number. Alacritty allocated 1.4GBs during startup while Xfce can keep it within 20MBs. Any plans to allocate memory a bit less aggressively if such high number is used? Sure, without scrollbar it's kinda pointless anyway but when it gets implemented it can be useful. Thank you

steinuil2• 8 years ago

Has the input latency improved any? I liked alacritty, but I switched to mlterm after a while because the input latency was really bugging me.

jwilm8• 8 years ago

Thanks for this feedback! We haven't heard a ton of complaints about the input latency, and comments like this help us to prioritize issues. This has been mentioned in two discussions today, so perhaps it's time to address this.

If you want notifications on any developments here, please subscribe to this GitHub issue: https://github.com/jwilm/alacritty/issues/673

steinuil2• 8 years ago

Thanks, I'll definitely be looking forward to any improvements on that!

pcwalton• 8 years ago

Regarding tabs, macOS has native tab support more or less built-in to the windowing system—you can see this in action if you create a document-based app in Xcode—but your app has to be structured in such as a way as to opt into it. Have you considered opting into this or would you consider it contrary to the project goals?

jwilm8• 8 years ago

The hardest part about supporting things like this on macOS is that they often require a lot of additional code or a certain design whereas on Linux, a lot of these features are provided by the window manager.

I don't consider it contrary to the project's goals if it's something that can be done unobtrusively. Given your description, it sounds like this may be something we could support easily. I filed #1544 to track this. Thanks for the suggestion!

#1544: https://github.com/jwilm/alacritty/issues/1544

saagarjha2• 8 years ago

This is actually enabled by default unless you disable it. No extra code needed, unless the macOS implementation conflicts with yours.

mindB2• 8 years ago

These benchmarks miss the point in my opinion. When I'm choosing a terminal emulator, beyond features, the one "performance" metric that I'm interested in is latency; nothing else really affects my workflow (positively or negatively). In the benchmarks I've seen of alacritty wrt latency[1][2], it doesn't come out so well.

[1] https://danluu.com/term-latency/

[2] https://lwn.net/Articles/751763/

jwilm8• 8 years ago

"miss the point" feels a bit strong. Rather, I get the impression Alacritty's values don't match your own values in a terminal emulator, and that's totally OK. Historically, input latency hasn't been considered a big pain point by most users.

That said, we do have a plan[1] to address this issue and be both high throughput _and_ low-latency.

[1] https://github.com/jwilm/alacritty/issues/673

mindB2• 8 years ago

Fair enough. :) I guess my stronger wording is because I don't understand workflows where being able to dump vast quantities of text to the terminal quickly is important. In general, a terminal emulator is for use by a human, and humans can't really process info at the throughput rate of other terminal emulators, much less the faster alacritty.

All that said, I'm glad to hear there's a plan on the latency front.

nixpulvis• 8 years ago

I'm really happy to see all the hard work come together on this. I think the project has a great new feature.

O_H_E4• 8 years ago

What possible use cases where such high scrollback speeds could be useful?

L0stLink3• 8 years ago

Performance is never a bad thing, even if I don't always need my terminal emulator to be able to handle large amounts of text, there is nothing wrong with having a light weight high performance (eventually cross platform, hopefully) modern terminal emulator. I read a while back that implementing the same in iterm2 (a popular macOS only terminal emulator) is challenging due to past design decisions [0]. Certainly in a time where hyper terminal[1] (based on electron) exists, I see no downside to having the option of Alacritty.

[0] https://news.ycombinator.com/item?id=17635869 [1] https://hyper.is/

O_H_E4• 8 years ago

It is certainly not a bad thing, was just asking out of curiosity

nullify88• 8 years ago

Performance is never a bad thing

Depends on your priorities and what you are willing to sacrifice for it. High bandwidth terminal emulators will cost CPU and battery life. I'd opt for longer battery life.

The choice is nice to have though.

aktau• 8 years ago

This sounds great, especially the fact that v0.2 has much improved throughput over v0.1 in most cases. I must however echo some other posters' sentiments: latency is even more important than throughput, and alacritty's input latency wasn't great last time I tested it (quite a while ago). Maybe it's been improved too, though no mention of it in the post.

Alacritty gets scrollback, publishes benchmarks

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