Hi
Installed the latest Sublime Text version 3 build 3143. As soon as I make it full screen on my 4k monitor everything on my macbook pro becomes slow to the point of me not being able to use my laptop. As soon as I close sublime text everything works fine.
This never happened before this version.
Anyone else experiencing same? Any solutions?
I have a pretty high end 2016 macbook pro 15inch with 16GB ram so this is unusual.
I have the exact same issue. If you’re using Material Theme, this seems to be the biggest culprit. It was not a problem at all with Sublime Text 2, but this upgrade makes my CPU and energy usage spike. ST3 is consistently at 15% to 20% and my Mac become slow.
For the record, I’ve done a complete uninstall and a clean reinstall, removed all most all plugins, and still the issue persists.
If I change the theme to the default, it seems to help. So I’m thinking the culprit is the Material theme (at least in my case). I hope this gets fixed soon!
Also, try deleting the data folder. Follow these instructions:
I am using Material Theme! I really like this theme 
Changing to the Default theme does it resolve issue completely or is just better?
Unfortunately it is one of the most bloated themes, because it tries to provide a couple of themes in one. As a result many entities are created in the background and need to be managed, which provide no value.
No sense. Materia theme just provide 4 separated theme files and 4 separated scheme file. Nothing is handled/geenrated live. And not all of 300k users have this issue.
No sense.
Unfortunately not. The problem is not caused by the number of theme and color scheme files, but the number of Theme Options each of the themes provides.
Each entity which is created, requires memory and needs to be handled by the theme engine, no matter whether the associated setting is true or false. This fact can easily proved by the RAM usage of ST. If a (let me kindly name it) “normal” theme is active, an empty ST window without documents, requires about 30MB of RAM on my Windows box. As soon as I apply either Material Theme or Boxy Theme, the RAM usage increases to about 60…90MB!!! (2x to 3x more!!!)
If you open many windows and maybe documents those themes can quickly cause much more RAM to be consumed and the GUI becomes noticeable slower even on 2k displays over the time. With a 4k display things might get even worse for sure.
What you do with the tons of Theme Options, was IMO never meant to be done with them.
Things would get much better if you’d split the few themes in many and heavily reduce the number of Theme Options per file.
Since i can’t reproduce this issue i can’t assume the theme is the cause. And even if material theme is the cause, it is not under active development since i switched to visual studio code (because i think ST is now obsolete).
Since i’m the main and only contributor on material theme, my opionion is also my choise. I’m open to PR. This CPU issue appeared from one of the latest ST builds and since i have not updated the theme for months… the only part changed is ST and its ‘new’ theme engine.
I’m facing the same problem after updating to Sublime 3. My MacBook becomes almost unusable when I start Sublime. I’m also using the Material theme.
I haven’t tested yet by deactivating Material theme, though, it won’t be easy for me if I had to use ST without MT.
I’m using MB Pro 16GB RAM, core i7. So this issue really is a pain. Hoping to find some solution soon.
I removed Material Theme and am using Default adaptive theme now and everything seems to be good so far.
ps: Sublime is definitely not obsolete … my opinion anyway 
@softinio you can also try Boxy theme, I liked it. Not as beautiful as MT, but pretty much same with appropriate settings. I provided my settings here: High CPU usage on Mac Sierra with 3143 - spent a few hours on it.
p.s., Sublime is definitely not obsolete. 
Funny enough I tested default theme over weekend and it worked fine with non-4k monitor.
Today I tried on 4k monitor and the same slowing of macbook happened again.
Guess a bug in ST then by the looks of it.
Will switch to using VS Code till this is fixed.