iMac 5K Retina extremely slow Mission Control

What's most frustrating about this is that I looked at the new 12" Macbook and Mission Control works perfectly.

That's right. My $4,000 iMac with 4GB of dedicated GPU can't drive this feature. But a $1200 Macbook can. Why? Because Apple probably put more time in QA for that product than they did for the new iMac.

From mgnagy: "What's most frustrating about this is that I looked at the new 12" Macbook and Mission Control works perfectly."

Mission Control works perfectly fine on my 5K iMac, too. For a couple hours. Did you play around on the 12" Macbook and run over 5 programs on it for a few hours and determine Mission Control worked perfectly? I highly doubt it. 🙂

Does anyone else feel like it's a lot better since this recent driver update:

https://support.apple.com/en-us/HT204779

It's not perfect by any means, but I feel like it's now quite useable even with "Reduce Transparency" turned off.

No, this didn't have any discernable impact...

no, it's not any better. Mission Control is completely unusable on my iMac, unless i enable Increase Contrast (which also enables Reduce Transparency by default). and even then, Mission Control still lags slightly when switching between desktop spaces—but you need to launch a bunch of apps in separate spaces, then start switching between them, before you'll notice the GUI lags. you can't just test with empty spaces.

so Mission Control is still BROKEN, and apparently Apple has no intention of fixing it. as i've said already, MC worked flawlessly in previous versions of Mac OS.

I took delivery of my 5k retina iMac just over a week ago. It has 32GB of ram but with the base model graphics card. Out of the box, I had problems with mission control animations and also the animations when switching between apps with cmd+tab. Mission control was unbearable. I updated to 10.10.3 and installed this driver update: If your iMac (2013 or 2014 model) restarts when opening a JPEG image in Finder or Preview - Apple Support. This made the problem much better and I was happy to use mission control. it was still a bit slow, but no where near as bad as it was. Sadly after a couple of days, the problem returned though, and this time there is even a lag when just clicking on a different window to bring focus to it. I updated to the 10.10.4 seed which fixed this all again on Friday, but now on Tuesday morning the problem is back again!

I do have a lot of apps open including Chrome with quite a few tabs sometimes, but this should not be happening! My previous machine was a 2012 Mac Mini with 16GB of ram and was super smooth with all this stuff. It's really disappointing.

yeah, same here on my late-2009 27" iMac, after using the machine for a while; opening apps on different desktop spaces, Mission Control gets very laggy, and unbearable to use.

Hello,

Same report here : iMac 5k 16 Go RAM and base graphics M290X, Mission Control can become very laggy. Annoying because it (was) is a nice function, eye candy and useful.

Hope this will be solved soon :-)

Hello,

Same report here : iMac 5k (i7) 24 GB RAM and base graphics M290X, Mission Control can become very laggy.

Apple has reportedly tried everything, including a diagnostic upload was performed. So far, no solution on the part of Apple. I have the impression .... in German "Apple is playing for time"

Hope this will be solved soon!!!

El Capitan fixes Mission Control for me, even without "Reduced Contrast". I have the base model retina iMac. Very happy here.

Any news regarding this issue...i have 10.10.3 and still have these problems when sclaing my display..

Same issue here, even with 10.10.3. Mission control extremelly slow without "increse contrast".

10.11. El Capitan Public Beta on iMac Retina

They promise that there should be significant improvements on Mission Control and Exposé

Anybody installed this already on an iMac Retina 5k (Basis Graphic M290X)?

Mission Control is still barely useable here... starving for improvements!

I have installed the developer Beta and so far so good! It's very smooth just like it should be. I'm pretty sure the OS is using Metal for these animations now. Long may it last!

El Capitan OS X improves the performance of OS X, including through better management of the graphics card. Result, the Retina iMac is much more fluid than before: the proof in pictures!

Watch video: https://youtu.be/AQDnQo2aY1w