[BUG] Slow scrolling/cursor movement on macOS with large window

[strayer]

What did you expect to happen?
Smooth performance when scrolling and moving cursor.

What actually happened?
Stuttery movement when the emacs window is maximized.

Additional details:
https://github.com/Strayer/dotfiles/tree/f6a037b/.doom.d

Video that shows the slow cursor movement:
https://youtu.be/54ozr4zPgTw

Profiler info with large window:

Profiler info with small window:

I'm using emacs 27 installed via homebrew:
brew install emacs-plus --HEAD --without-spacemacs-icon --with-jansson --without-multicolor-fonts

I did experience the same problem with emacs 26 too though.

System information:

((emacs
  (version . "27.0.50")
  (features . "RSVG IMAGEMAGICK GLIB NOTIFY KQUEUE ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS MODULES THREADS JSON PDUMPER LCMS2 GMP")
  (build . "Dec 20, 2019")
  (buildopts "--disable-dependency-tracking --disable-silent-rules --enable-locallisppath=/usr/local/share/emacs/site-lisp --infodir=/usr/local/Cellar/emacs-plus/HEAD-85a60da/share/info/emacs --prefix=/usr/local/Cellar/emacs-plus/HEAD-85a60da --with-xml2 --without-dbus --with-gnutls --with-imagemagick --with-json --with-modules --with-rsvg --with-ns --disable-ns-self-contained")
  (windowsys . batch)
  (daemonp . server-running))
 (doom
  (version . "2.0.9")
  (build . "HEAD, origin/develop, origin/HEAD 6d40f30a0 2019-12-20 05:01:44 -0500"))
 (system
  (type . darwin)
  (config . "x86_64-apple-darwin19.2.0")
  (shell . "/usr/local/bin/fish")
  (uname . "Darwin 19.2.0 Darwin Kernel Version 19.2.0: Sat Nov  9 03:47:04 PST 2019; root:xnu-6153.61.1~20/RELEASE_X86_64 x86_64")
  (path "~/.local/bin" "~/.poetry/bin" "~/.cargo/bin" "~/.bin" "/usr/local/sbin" "~/Library/Android/sdk/tools" "~/Library/Android/sdk/platform-tools" "~/.asdf/shims" "~/.asdf/bin" "/usr/local/bin" "/usr/bin" "/bin" "/usr/sbin" "/sbin" "/opt/X11/bin" "/Applications/VMware" "Fusion.app/Contents/Public" "/Applications/Wireshark.app/Contents/MacOS" "/Applications/VMware" "Fusion.app/Contents/Public" "~/.local/bin" "/usr/local/Cellar/emacs-plus/HEAD-85a60da/libexec/emacs/27.0.50/x86_64-apple-darwin19.2.0"))
 (config
  (envfile . envvar-file)
  (elc-files . 0)
  (modules :completion company ivy :ui doom doom-dashboard doom-quit hl-todo modeline nav-flash neotree ophints (popup +all +defaults) vc-gutter vi-tilde-fringe window-select workspaces :editor (evil +everywhere) file-templates fold format multiple-cursors rotate-text snippets :emacs dired electric ibuffer vc :tools ansible direnv docker editorconfig (eval +overlay) flycheck (lookup +docsets) magit terraform :lang data elixir emacs-lisp erlang javascript markdown (org +dragndrop +present) php python sh web :config (default +bindings +smartparens))
  (packages "n/a")
  (elpa "n/a")))

[hlissner]

Possibly a duplicate of #1301.

This is a general and common Emacs and MacOS issue, unfortunately: https://www.reddit.com/r/emacs/comments/d2n2wh/emacs_is_slow_on_macos/. Both are very prone to redisplay slowness like this.

You could try disabling line numbers with (setq display-line-numbers-type nil) and switching to our light modeline (but changing modeline to (modeline +light) in ~/.doom.d/init.el).

Perhaps this might help too:

(add-to-list 'default-frame-alist '(inhibit-double-buffering . t))

Also try another font. Emacs seems to disagree with some fonts. Fira Code is known to work well with Emacs.

If none of that helps, it may be beyond me or Doom to fix it. Emacs is, sadly, very prone to scrolling slowness, and much more so on MacOS than on Linux.

[strayer]

All of those do help, it seems. Fira Code also boosts scrolling performance considerably, which I find very annoying (I like Pragmata Pro!).

Its still much slower when maximized compared to the small window (or actually ANY other editor/IDE I have on my machine like Neovim, VS Code or IntelliJ IDEs), making emacs still quite annoying. After some more reading it seems like rendering on macOS is simply a second-class citizen for emacs. Ref: https://www.reddit.com/r/emacs/comments/del1yl/emacs_high_gpu_usage_on_mac/

I tried an Ubuntu VM just for fun, but the performance of VMware Fusion with retina-resolution apparently sucks too much to compare anything.

[zyeri]

Also try another font. Emacs seems to disagree with some fonts. Fira Code is known to work well with Emacs.

Is there a list of fonts known to work well with Emacs? I'm using Iosevka and am experiencing similar issues with scrolling/movement speed under macOS.

Edit: Emacs is installed as brew install emacs-mac --with-modules --with-rsvg --with-natural-title-bar.

[pcesar22]

I have the same exact issue. My macos setup behaves exactly like OPs video.

FYI, display-line-numbers-type and the inhibit-double-buffering didn't do much for me. Changing the font to "Monaco" did the trick. Like OP, it is still not "buttery-smooth" but now at least I get about the same scrolling performance as spacemacs.

[auwtch]

@zyeri I'm also using Iosevka with emacs-plus and have the same problem, for example in spacemacs scrolling was smooth, maybe they have some workaround.

[pcesar22]

@testarossaaaaa Yea spacemacs seems to not suffer from this despite being emacs based as well... I've enjoyed doom immensely and for me this is the only thing stopping me from making the switch :(

If anyone knows some sort of workaround I would greatly appreciate it!

[dsdshcym]

One difference I noticed between spacemacs and doom-emacs is the value of scroll-conservatively:

• In spacemacs, scroll-conservatively = 101
• In doom-emacs, scroll-conservatively = 10

Maybe you can try (setq scroll-conservatively 101) and see if it helps?

[hlissner]

I've set scroll-conservatively to 101 in 8c7aaa6. I don't think it'll help with OPs issue specifically, but it may help with page-wise or long-distance motions, as recentering the window can be expensive. Still, I am no closer to figuring out what Spacemacs does that we don't. If anyone can bisect their configs until the issue goes away, and narrow down its origin, it'd be a huge help.