Tangential, but I really wish there would be a performance renaissance with Emacs.

Native-comp was a good step forward, but Emacs is still so much slower than Neovim, even in the case of launching and immediately quitting, with no config:

    $ time emacs -Q -e kill-emacs
    /Applications/Emacs.app/Contents/MacOS/Emacs -nw -Q -e kill-emacs  0.18s user 0.03s system 98% cpu 0.213 total
    
    $ time nvim -es --cmd 'vim.cmd("q")'
    nvim -es --cmd 'vim.cmd("q")'  0.02s user 0.01s system 82% cpu 0.034 total

Emacs is my favorite editor, full stop.

But every time I open Neovim or Sublime for quick tasks, it's always painfully apparent how much faster they are when I CMD+Tab back to Emacs.

Emacs' hard to solve issue is its use of global mutable state all across the board, which makes concurrency and parallelism very hard to add properly. It will take a lot of effort to slowly carefully reduce the error/bug surface and add proper parallelism constructs, that are easy to use for any package author.

While faster Emacs would always be nice, I think the idea is you just keep it running. Hence emacsclient program. So startup time is not such a big deal.

On my M1 Mac Pro I get 0.13s wall, so not much faster than your Mac. On my i9-9900K Linux box I get 0.04s. I would think my M1 single core performance would be on par, if not faster. Perhaps it has something to do with macOS and gatekeeper, as I notice I'm not getting as high of a CPU utilization.

    $ gtime /opt/homebrew/bin/emacs --batch --eval '(princ (format "%s\n" emacs-version))'
    30.2
    0.07user 0.03system 0:00.13elapsed 78%CPU (0avgtext+0avgdata 46064maxresident)k

    $ /usr/bin/time ~/bin/emacs --batch -eval '(princ (format "%s\n" emacs-version))'
    30.2
    0.02user 0.01system 0:00.04elapsed 95%CPU (0avgtext+0avgdata 57728maxresident)k

> Emacs is still so much slower than Neovim, even in the case of launching and immediately quitting

I agree, but there's ways around it. On my machine the Emacs daemon is ready before I even log-in (lingering [^0]).

I think I only restart the daemon when I update emacs and its packages, and yeah, Emacs and Spacemacs are slow, but do not slow me down.

[^0]: https://wiki.archlinux.org/title/Systemd/User#Automatic_star...

Emacs is functionally a shell not an editor. Starting Emacs for each file is akin to starting and stopping Wayland for every web page you open.

So the miniscule increase in start time is a non issue

Emacs can certainly be sluggish, but I'm not sure how much that's e.g. inherent to ELisp, or due to synchronous/single-threaded code, or choosing slow algorithms for certain tasks, etc.

For me, the best performance improvement has been handling long lines; e.g. Emacs used to become unusable if it was given a line of around 1MB. Since I run lots of shell-mode buffers, that would happen frustratingly-often. My workaround was to make my default shell a script that pipes `bash` through a pared-down, zero-allocation copy of GNU `fold`, to force a newline after hitting a certain length (crossing a lower threshold would break at the next whitespace; hitting an upper threshold would force a break immediately). That piping caused Bash to think it wasn't interactive, which required another work-around using Expect.

Thankfully the last few versions of Emacs have fixed long-line handling enough for me to get rid of my awful Rube-Goldberg shell!

What hardware are you on?

On my old Ryzen 3600X running Arch it's a lot faster. Does the UI eat so much performance on OSX?

  $ time emacs -Q -e kill-emacs
  real    0m0.076s
  user    0m0.058s
  sys     0m0.018s

  $ time nvim -es --cmd 'vim.cmd("q")'
  real    0m0.028s
  user    0m0.005s
  sys     0m0.003s

my non-command line gui version of doom emacs with a bunch of packages enabled loads up fully for me in 0.45s which is hardly slow. sure it's slower than neovim but also not slow in the absolute sense and i don't have the emacs daemon running which would make that even faster.

/usr/bin/time emacs -Q -e kill-emacs 0.03 real 0.02 user 0.00 sys

Altough I'm not using Emacs.app.

I share your wish. Emacs, as wonderful as it is, has accumulated a lot of cruft over the decades and would benefit immensely from a rewrite. A "Neo-Emacs" could be multithreaded from the ground up and drop support for archaic platforms. The rewrite could even be in Rust to attract younger developers.

I'm not sure I'm capable of noticing or caring about the difference between 0.18 and 0.02 seconds for something that doesn't happen on a rapid cadence.

Startup time does not matter, use the daemon. Opening a new frame is ~instantaneous.

I practically live in Emacs and it's not slow at all. It's very zippy, and my setup isn't the lightest!

There's a new branch (feature/igc) with incremental garbage collection (via MPS) that makes routine actions faster. I've been using it and it has been incredibly stable and has completely eliminated stutters (which used to happen very infrequently, but were present). Also, to me, it seems like it improves latency. The cursor feels more responsive.