Q: UI Lag in El Capitan

I am also having this issue. Things like opening safari, switching between desktops and general UI animations are choppy on my mid 2013 retina Macbook pro. I have created a "standard" test user and the animations improved dramatically. So for me it seems like only one user (administrative) is being affected.

I might have a solution for the lag problem.

So I've had this problem with my Macbook Pro (Retina, 13-inch, Early 2015) OS X El Capitan, the lag was just horrific, switching fullscreens was a nightmare and everything just seemed to lag lag and then lag some more, I've tried tons of solutions suggested by many forums, from reseting the PRAM and SMC to trying to change the display's resolution and even tried to erase and reinstall the OS but unfortunately none worked, I've literally spent weeks trying to figure out a solution, until I started noticing that the lag was the worst during daytime and that it was an intermittent lag, and one day I was sick of how much automatically adjusted brightness was annoying so I just turned it off and to my surprise the lag immediately stopped, it turns out that that feature was the culprit and the lag appeared only when the screen brightness was changing automatically and now my Macbook works like a charm, so here's what you can do:

Go to System preferences - Displays, and uncheck "Automatically adjusted brightness" in the "Display" tab.

I hope this works for you as well.

Ok fine, but why deactivating this function system improve its performance?

I honestly have no idea, It just worked, that's all I know and it's still working till this day

Did it work for you?

I honestly have no idea, It just worked, that's all I know and it's still working till this day

Did it work for you?

I've just try the solution and seems to work. The lag went away. Probably the auto-adjust didn't sets only brightness level but executes some other image elaboration. I don't know.

Hey guys,

i've been looking for a solution of the UI lag for my MBP, early 2015, quite a long time. Animations were extremely laggy.

Today, I found this post and switching of the function "automatically adjusted brightness" solved the problem. I don't know why, but I'm very happy.

Thank you very much for the tip SoonaS!

More than happy to help :-)

THANK YOU!!!!!!!

It helps me a lot!!!

Ive been confused by this jerky problem for a long time, and I tried different ways to solve this, but no one worked.

Finally, I can use my laptop without any mysteries intermittent choppiness.

Maybe try to run the code listed on this website:

https://david.gyttja.com/2013/01/21/fix-lagging-display-performance-on-retina-ma cbook-pro/#comment-56910

Definitely worked for me. If it still doesn't work for you, also try removing extra desktops from Spaces/Mission Control.

Try to also get oriented with OnyX, I know it doesn't really "speed up" a Mac, but it helps clear and rebuild possible corrupted data.

Hope this helps!