Yosemite OS UI animation lag

I did a test today just to see what would happen if I installed the official 10.10.1 release onto an erased partition. My current Yosemite installation started as a beta 3 install, and was simply updated from there.

Quite a bit of difference. I didn't do any other tweaks or tricks like deleting the mentioned preference file, or adjusting the contrast in the Accessibility panel. There's a bit of lag yet in the window animation when opening folders, but nowhere near as choppy as it was. Which I think kind of proves what I was after; seeing if leftover beta code was causing some of the problem. Overall, Yosemite is now much more responsive.

I like to use OnyX to turn off all GUI animations to speed up the desktop. I want windows to just snap open and close. The animation stuff is just eye candy and adds nothing to functionality. Once I did that, then Yosemite really sped up visually.

So anyway, something to try if you installed Yosemite over the earlier beta releases, or over an older version of OS X such as Mavericks.

Hey Kurt thanks for the info. How long did you test this out? I've noticed that everything is snappy and awesome when I first reboot, but after a few hours it slows to a crawl.

Only for about 15 minutes. I did this kind of at the end of the day. I'll have to give it a longer workout to see hoe it holds up under real use.

Thanks for the tip! I'll have to give that one a try.

It really depends what app you use.

if you boot, open matlab, chrome/safari, preview, mail, it will lag as **** after 10 minutes. it really depends. So sometimes it is smooth for 24h, something's only for 10 minutes.

Wow, fiddling with "contrast" in "accessibility" worked. This has been driving me crazy, the delay would get so bad that I would have to shutdown and startup again several times a day - especially in intense Photoshop sessions. This with a Mac Pro with 20 GBs of RAM. (My MacBook Pro runs as expected with Yose.) I retreated to Mavericks (which was snappy) on another drive and re installed Yosemite more than once only to have the problem resurface. Thank you ds10320

Thanks for posting this. I tried this previously and didn't notice a real difference, but with the latest build tried it again and it DID WORK. Amazing. It doesn't help a couple other Macs here, but it does solve the UI context switch lag that was driving me INSANE.

Thanx for the contrast tip, it worked for me. Now I have a iMac that I can work with, without going crazy over the lag.

Here I was thinking it was desperately time to upgrade my 2010 MBP. All because someone can't program a UI...Literally all lag has disappeared after increasing contrast (which I guess I can't get used to). I even had typing lag!

Appreciate the solution, just wish apple could get on fixing this type of stuff that makes the UI unusable/unpleasant. Maybe don't update every year for once and just fix what you do have???? What do I know.

You are far from the only one with that sentiment. I'd much rather they release a polished OS every few years instead of this, "Cram as much into another release as quickly as possible!" approach.

The real fix is to check "reduce transparency." It's really expensive for the computer to make a window look like fogged glass… it has to figure out every layer behind the window. Having multiple displays and/or a bunch of windows open can really slow things down.

The "increase contrast" fix works because it also enables "reduce transparency."

It is expensive. But it work smoothly but after 1-2-3-4-5 hours, it start to goes lag. At this point, reducing the transparency doesn't change a lot, it stays very laggy. Without a reboot, then mission control takes 3-5 seconds before showing up. Gesture with 5 fingers to show the desktop barely works, is very slow or the animation stop in the middle. At the end, moving a window become laggy as well.

There is a VERY SERIOUS bug behind it. I would put this bug at the top priority if I was Apple. But I thing it won't be fix until 10.12 or 10.13. So, if someone want to computer that works, 2 solutions. The first is to install windows instead, the second one is to buy another computer with windows. Apple looks like they want to push us to stop using OS X.

I am experiencing the same really annoying issue. The UI gets more and more slowly over time. When I restart, everything is super smooth, even when I open 10 hungry apps right away. After a while, the performance decreases, and even if I quit every app except for one, the mission control is still really really slow.

Since the lag is building itself up over time and it seems to happen as well on retina MacBooks, 17"-non-Retina-MacBooks (such as mine), and even retina iMacs with really fast hardware, it seems unlikely to be a hardware issue, but has to rather be some programming bug.

Disabling the transparency in the settings performs a miracle, but unfortunately I can't enable it without also checking the increase contrast checkbox, which makes the UI look quite ugly in my opinion, and isn't really a worthy trade for a faster mission control.

I have done a fresh Yosemite install, without much success. Also I have tried the resetting-the-PRAM-and-deleting-some-files fix previously mentioned- no success. It all seems to work, but I suppose it is merely the effect of the system restart.

I would like to ask if someone who had success with the fresh-install-of-yosemite fix did restore his system afterwards using time machine, or not.

When I did my fresh install, I was wondering if maybe the files that were causing the issue were restored when I restored my user from time machine. I did not click on "restore system from time machine backup", but instead I installed yosemite from scratch, and then when it asked me to create a user, I said restore personal documents and Applications from my time machine backup.

Do you think I could fix the issue by doing another fresh install of yosemite, but then create a new user instead of restoring my old one? I would have to migrate all my files, documents and applications manually, so it would be a ton of work which I don't want to do unless it has a good chance of success...

I am experiencing the same really annoying issue. The UI gets more and more slowly over time. When I restart, everything is super smooth, even when I open 10 hungry apps right away. After a while, the performance decreases, and even if I quit every app except for one, the mission control is still really really slow.

Apple massively changed the way RAM is used in Yosemite. The common theme I'm seeing is a Mac runs very smoothly to start with, then keeps getting slower. To me, that means RAM that should be being released when an app is closed, isn't. That forces apps still running, and others just launched to use virtual RAM, which means the hard drive is being used as RAM. Drives are hundreds of times slower than RAM, so performance suffers greatly when that happens.

Anyone who feels like testing could maybe verify this as a possible issue. Restart your Mac so it's at a clean state. Launch a few apps you commonly use and do a few minutes of work with each. Download and run EtreCheck. Copy the current virtual memory info at the bottom of the information EtreCheck returns to a TextEdit file. Keep using your Mac until it shows a considerable slowdown. Run EtreCheck again and get the virtual memory information again to see if it has changed.

What I'm kind of expecting to see is that VM use is low to start with, and high page out counts when the Mac is running slowly. So you would then post back something like this:

Installed RAM: 16 GB

Mac running fast: (the EtreCheck data you saved to a TextEdit document earlier)

Virtual Memory Information: ℹ️

13.27 GB Free RAM

2.33 GB Active RAM

535 MB Inactive RAM

1.03 GB Wired RAM

479 MB Page-ins

0 B Page-outs

Mac running slowly: (the EtreCheck data you saved to a TextEdit document later)

Virtual Memory Information: ℹ️

13.27 GB Free RAM

2.33 GB Active RAM

535 MB Inactive RAM

1.03 GB Wired RAM

479 MB Page-ins

4 GB Page-outs

My "results" are fictional here. Just an example of what you might see.