iTerm2 3.3

This likely isn't CPU throttling at all. iTerm by default uses the faster Metal renderer when your MBP is plugged in, and a different renderer when not. You can adjust this so that it always uses Metal by following the instructions on this page: https://gitlab.com/gnachman/iterm2/wikis/Metal-Renderer

If you live full time inside iTerm, I would highly recommend reading over the documentation and becoming fully familiar with the different aspects of it and what you can tweak. Despite it being something that merely "displays a matrix of a few thousand characters", it is still a very complex piece of software and knowing at least a basic level of its configuration will likely be worth it.

There is also throughout. Some programs have real problems rendering large amounts of output, i. e. when tail'ling logs. This was a significant problem with Hyper, for example, but they have changed the backend library and it's fine now. I believe the reason here is usually a lack of bouncing, i. e. rendering for every new character even if they arrive faster than the refresh cycle.

It's not entirely unreasonable that rendering takes some time. Terminals have evolved and, as but one example, character widths now vary even when using monospaced fonts (non-ascii characters, emojis, whatever). Then, there are fancy additions like ligatures, transparency effects, etc.

IIRC iterm2 has a setting to disable gpu rendering while on battery which is almost certainly your issue.

It can be super slow. I've compared scrolling in Vim and Emacs on the same (large) json file and Vim is painful and Emacs is almost immediate.

> I don't understand the technical challenge of parsing a protocol that would literally work on a real VT100 sans some escape sequences and colours.

We definitely ask a lot more of a terminal today then we did of a VT100.

First, it's not really a grid anymore: double-width CJK characters and emoji break that assumption a bit (though it still holds if you just consider them as 2-column glyphs). Our fonts are nicer: we have vectors not bitmaps, anti-aliasing, ligatures, combining accents. Color, but also effects like bold/italics. iTerm2 is also capable of images (even before this release, which added sixel graphics; it can output some other format (PNG?) with a special escape.) iTerm2 will dynamically wrap lines (it remembers where actual ␤ chars are, and if you resize, it can re-wrap the lines appropriately). It can pick out URLs, and make them easily clickable/copyable. It tracks the timestamp of each line of output (press ⌘⇧E by default, or View → Show Timestamps). And it's doing this on top of an OS that is also mux'ing your display out to multiple applications (windows), shared with the same CPU that is driving the programs emitting the output into the terminal (it's not dedicated hardware).

And the terminal protocol is not really simple… some aspects of it rely on how fast input comes from (this only happens on the input side, I think, and there's a varieties of "if this, then this sequences means X, otherwise it means Y".

I too would ask for better perf from iTerm2 (I get much better perf from Terminator on Linux — but it doesn't have quite the featureset that iTerm2 has, I think) but I do think that there's a lot more going on than one might give the emulator credit for.

> The only terminal emulator that has decent performance scrolling and resizing Vim buffers Alacritty.

I've not used Alacritty, but my understanding is that it (intentionally) has a much narrower feature set to support. (I personally prefer something feature-ful like iTerm2.)

> I'm on a 2018 MacBook pro.

I've actually wondered if this is part of it. I get low perf from not just iTerm2, but my system in general. I've looked for, and not really found, a way to see what the core temps are (I've mostly found this, but the numbers are rough) and whether it is being thermally limited (I have no idea). The MBP's limited intake/exhaust areas just feel to me that they would significantly limit the thing's ability to dissipate heat. (E.g., my Lenovo has much more surface dedicated to airflow, and I seem to get better perf from it. The Lenovo also gets hotter too, so… IDK. But it also runs Linux and Terminator, so it's hardly an apples-to-apples comparison.)

1. Built in password manager (command-alt-f) for the Times you’re stuck with ssh passwords

2. Output triggers: iterm can run actions in response to certain text on stdout: I use this to insert a mark at each terminal prompt line and when the phrase “NOTICE ME:” is detected. This way, I can use iterm’s mark navigation features to quickly jump to interesting lines

3. Finally, the biggest advantage of iterm is its ability to auto detect soft boundaries like vim vertical splits and restrict selection to one side or the other of the split.

I personally find the following either cool or really productive;

Open Quickly, Undo close, Triggers, Smart Selection, Instant Replay, Regular Expression Search, Save Mark/Jump to Mark

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4572953/

    # Title     Min     Max     Avg     SD
    1 Zorc      2.9    33.2    12.5    5.6

But I don't know why anyone would choose to use that on a Mac. The UI requires initiating connections to remote systems (or "localhost") through the GUI -- which feels really backward when you can just open a new window/tab on any other terminal app (for local tty sessions) or run ssh from the command line (for remote sessions).

https://www.iterm2.com/3.3/documentation-status-bar.html

If you hit rainbow and hate it, just remove the items and re-add them and they'll go back to normal. :)

Developer is responsive and it adds enough to the experience to make it worthwhile as a wrapper.

For example, re-create a layout of multiple tabs with specific split panes for each project.

Previous attempts before this API were a struggle:

- You could almost do this with Saved Window Arrangements but not quite and there was no association to a project.

- You could also hack something with profiles if you're willing to make a profile for each project, but it still doesn't get you there.

- Bury Session is the closest which pretty much does what I want but it keeps all of the tabs running in the background. This can be a lot when you have 5-10+ tabs open each across multiple projects. No way to "sleep" a buried session that I could find.

- I also tried implementing it via the previous AppleScript API and it turned out to be a lot harder than expected to open "2 tabs with 3x2 split panes each and run commands x, y, z, ... in them". Then I called the AppleScripts via Python so I could template them more easily. I got about halfway there.

I also have some helpful triggers, which I currently have a wiki page explaining how others at my company can set up. It looks like I could replace those instructions with a single command using one of these scripts.

Those are the two things I've been wanting to automate for a while. After doing them, I imagine there will be plenty of things I never thought of before but will now that they're possible.

The reason I stick with VSCode even though it's slower than other editors is because of the features.

Hyper has non of those.

As for pasting, what shell are you using that doesn't support paste bracketing?

The only reason I downloaded iterm2 many eons ago but stayed for the rest

Why _not_ use tmux? It is pretty fantastic software, and IMO provides a much better interaction model. iTerm itself is even integrated w/ tmux through control mode.

Cmd + Shift + D

Or better yet, just use tmux!

:)