Sublime Forum

Slow rendering with "alt-tab"


I use a window switching app with Macos called “alt-tab” and when switching between Sublime and another application like a browser, Preview (pdf viewer), etc, the switching doesn’t occur requiring multiple attempts. This random inconsistency is frustrating-- no “pattern” to adapt to.

I’ve only observed this behavior with Sublime: other text editors switch consistently so I’m guessing that it’s Sublime’s rendering lag that’s the issue.

My questions

  1. if my theory right that the cause of this is rendering time, can this be improved? I have opengl hardware acceleration “Renderer” set to Apple 1M Max.
  2. are there other ideas for improving performance of sublime with alt-tab (for anyone out there who may be using that app) and in general?

Version running: build 4126




Does it happen in safe mode?



Hi, I been testing with safe mode on and this behavior has persisted.

Anything I can do, assuming that Sublime’s slowness to render is the issue? Per my initial support request, my hardware seems plenty fast…




Does it still happen if you set "hardware_acceleration": "none"?



I changed Preferences.sublime_settings, "hardware_acceleration": "none" – this had no effect.

I see this output/ errors, below, in the console on restarting Sublime – is there a missing config file that could be at issue – specifically, Unable to open /Users/jm/Library/Application Support/Sublime Text/Packages/Default/Preferences.sublime-settings ?

first paint time: 11.5854
Traceback (most recent call last):
File “/Applications/Sublime”, line 1082, in on_window_command
res = callback(w, name, args)
File “/Applications/Sublime”, line 152, in profiler
return event_handler(*args)
File “/Users/jm/Library/Application Support/Sublime Text/Installed Packages/Typewriter.sublime-package/”, line 101, in on_window_command
if not window.active_view().settings().get(‘typewriter_mode_scrolling’):
AttributeError: ‘NoneType’ object has no attribute ‘settings’
Unable to open /Users/jm/Library/Application Support/Sublime Text/Packages/Default/Preferences.sublime-settings



What’s the exact keys you use to switch apps? It could be a keybinding in ST is conflicting.



option + tab

Note that I remapped the caps lock key within the OS system preferences to option and use that key with tab as well.




I can’t reproduce the issue with alt-tab and ST in safe mode (ie. without any plugins). My guess is you have a keybinding or plugin that has a key binding for alt and that’s interfering with alt-tab.



I run into this on my Intel MacBook Pro, although I’ve hit it on at least one other application also. I haven’t pinned it down to anything specific. It does seem more commonly to occur if ST has been in the background for 60s+. It is almost as if there is a stutter in sending data to the GPU.

I also see something similar with key presses. Sometimes I have to trigger a secondary input event to get the previous one to show up.

This is a 2020 16” Intel MacBook Pro with the Radeon Pro 5600M.