iMac slows down after Big Sur inst… | Apple Developer Forums

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Hello!
I downloaded the macOS Big Sur image on MacBook Pro, then installed, everything works fine.
I started downloading the macOS image on iMac, but at the end I constantly got a loading error. Then I install image on USB from MacBook and installed it on iMac. After installation, iMac began to slow down, for example, it opens a folder in a few seconds or or launches the browser in 10 seconds.
With what it can be connected?

iMac (Retina 4K, 21.5-inch, 2019)
Serial Number C02Z1085JWDX

macOS

58k

Posted by

Kirill1104

Reply

Hi! I have an iMac27" late 2014 and after I installed Big Sur 11.4 my system with 32GB of RAM and this (shit!) Fusion drive system is come really really slow... until to 15/20 min to lanch an app!!! And I think with the next versione of macOS 12.x it will be definitly "dead" for Apple... so I decide to remove macOS at all and try to install Ubuntu or other GNU/Linux based distro. I am an Apple user from 1995 and this make my really un-happy... No good solution I have found to solve this issue, the only one seams to be just only change internal drive with a full SSD disk (pity this means 3/400 Euros...)

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FScarfato
I have 27” imac late 2014 i7 cuad qore turbo ram 32g with frigin fusion too. 3tb. The best part is only 128g is ssd. Balance is hdd.definitely not obsolete yet with fast moving tech. Just like cr7 n messi. Still relevant. anyway. Same prob. Mac os big sur slow. Apple consider our mac is vintage. My solution, i drop fusion. Keep the 128 ssd bought new 500g ssd. Partitioned. Then reformat to mac os catalina. This is the way! This is the way p/s convert hdd to externals. N set up NAS. Network attached storage. Wireless. But lagging when accessed

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Hilmi21_zul
Clearly Apple has gone to the dark side with a nasty update. You know they know (if we could only get an Apple employee on the OS dev team to speak LOL). They made an update that's good for some models (and their profit margins), but destroyed perfectly good computers with a dirty move. I am furious with this I'm not buying another mac ever, because somewhere in the near future I'll face the same putrid ***** because of another lame thing they do for their profits. Windows/bootcamp are my future

—
dreganism

Replies

Same here :( first load takes around 1 min, with catalina it took about 10 seconds.

Posted by

kenramirez

Perform a clean installation iMac (Retina 5K, 27-inch, 2017) Big Sur working perfectly.
Radeon Pro 570 4 GB

Posted by

Digiitalex

Same problem with 2017 iMac. Just upgraded to Big Sur. Now launching apps takes minutes as the icons bounce up and down. No indication in Activity Monitor of anything taxing the system. Tried to return to Catalina with no success. Used Internet Recovery Mode to attempt a clean install from scratch and I'm still having the same problem. Lots of spinning rainbow wheel and waiting, waiting, waiting.

Posted by

jrpembe

To the user saying the machine where they did a clean install is OK, after my initial problems, I did this. Reformatted , and did a clean install. The problems remained.
It seems to be some particular hardware combinations that are having problems. Possibly Apple did not get the proper beta testing done with Covid.
On a 2017 i7 Fusion machine, Big Sur for me runs fine, On my 2019 iMac Pro using an SSD, it does not. On the former it does not seem much different from Catalina. Boot is possibly one second slower, but programs run OK and really everything is fine. On the latter, I used to get faster booting 30+ years ago, loading using a tape!....

Posted by

ttelmah

Ridiculous! 2017 iMac with fusion disk and 40Gb RAM boots slower than my 2012 Macbook pro with Catalina.The overall speeds looks fine, but the start... oh my.
Anyone have good resources on how to perform clean install and roll back from Big Sur -> Catalina?

Posted by

Domshia

I downloaded big sur on my 2018 mid spec MacBook Pro with touchbar and everything works Perfectly fine. Now that I’m back home I also wanted to update my 2017 4K 21.5 iMac. But it’s the same as all of you others say, loading takes forever and even something like starting Safari takes five seconds. I hope it really gets better over time.

Posted by

MatushF

My Imac has slowed down also. Not only in initial loading but my large files freeze photoshop and makes working with them impossible. This change was not immediate, however. Big Sur was installed a few days ago but I started noticing problems this morning. Perhaps there was an automatic update overnight. I have 48 gig of memory and my hard drives have plenty of space.

Posted by

sergioas

The same problem here!!
After the update to Big Sur my Mac gone So much slower, it takes more than 2 minutes at the start-up vs Catalina 24sec!!!!
iMac (Retina 5K, 27-inch, 2017)
Processor 3.4 GHz Quad-Core Intel Core i5
memory 40 GB 2400 MHz DDR4
Graphics Radeon Pro 570 4 GB

Please fix this issue.... I feel like I'm working on Windows ;(

Posted by

klaudio001

Same here :( windows style

Posted by

toxdesignro

Same here.

iMac Retina 4K, 21.5, 2017

3.4 GHz Quad-Core Intel Core i5
8GB 2400 MHz DDR4
Radeon Pro 560 4 GB

Posted by

hdnsameera

Resetting SMC and NVRAM helped! iMac started to boot as usual (about 20 sec) and all programs appear ultra fast. Hope this helps you

Posted by

AndreyKitaev

Forgot to say: to reset SMC on iMac just pull out the power cable and wait a little bit.

Posted by

AndreyKitaev

It is embarrassing and frustrating to see a copy of a 3.7GB file to a flash drive in 43 minutes. My MacbookPro14,1 and an iMac19,2 are having the same problem. It's hopeless.

Posted by

MiriamP

Yeah, it's an absolute disaster. My boot up time takes almost 2 minutes just to get to the screen to type in password to enter the OS and then after that takes another 2 minutes to the point I can start using computer. I noticed dropbox takes forever to start up where on my other computer it boots up just fine.
The boot up time is definitely frustrating. I just couldn't believe it and overall it's just sluggish and takes 10 seconds to open a browser or another program and I have a 32gb ram, i7 imac with top video card.
I reset SV and VRram and it didn't solve anything.
I am very disappointed to say the least. It's embarrassing when windows boots up faster. I also only have one login item and that's dropbox only. I have hardly any extra stuff on my computer.
The boot up times from previous version went up 300% to 500%. It's just crazy.

Posted by

boydp182

I am having a same problem, it looks I am working on a windows.

Posted by

Manpasand