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 problem with iMac 21,5 2017, started right after the Big Sur update, can't believe they let this happen in official release 😞

Posted by

AndreyKitaev

I have the same problem. Using MacBook Air 13 inch (2015). I think the problem is some sort of nvme/ssd putting to sleep too often or snapshotting current memory on ssd/nvme then resume from there.
After restart or resume safari and other apps needs a lot of time .... like everything is frozen for 20-30 seconds even typing password at screensaver !
Catalina was super fast ! At least 2 times faster. Wonder if i can go back from my Time Machine ?
Problem is that system firmware was also updated .... and the problem may be there too ?!

Posted by

sanitariu

A similar problem. slows down graphics, scrolling, animation.

lags when typing and erasing text, lags in any applications, especially noticeable when scrolling through pages in safari.
MBP 13 2020 i5 16gb-ram

Posted by

Lip_art

Same here on 2019 iMac 27", i5 3GHz, 40GB ram. The boot process has slowed down enormously and the loading of the programs after login takes significantly longer.

Posted by

mimagast

Help Apple, please! Update as soon as possible!

Posted by

Mike123456789

dont think apple will fix. 2016 n older will not be compatible with big sur n newer. This strategy is for us to buy new one. And they stop giving out older os. Like sierra n catalina. Dont update new os

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Hilmi21_zul

MacBook Pro (Retina, 15-inch, Mid 2015)

2,2 GHz quad core Intel Core i7
16 GB 1600 MHz DDR3
Intel Iris Pro 1536 MB

And can't f*ing scroll the pages fluently or change desktops fluently after Big Sur update.
Even my Visual Studio Code which used to work perfectly before the update is clogging now.
Why would you do that to your clients, Apple? Is it again like with the iPhones where you had to admit you were slowing them down just to force people to buy new? This MacBook is worth more than two average salaries where I live, this is completely immoral.

Posted by

VivaceNonTroppo

My MBP is brand new (2 weeks old) and I accidentally updated from Catalina to Big Sur. what a disaster. all animations, scrolling typing video is disastrous now. this is the most buggy crap apple rolled out.....ever. typing these lines is already painful. do the apple clowns have absolutely no shame? I use macs for work, but now have to consider switching . Apple has totally lost it and now they are loosing even the most faithful mac lovers. bug fix? ever? customer support?

Posted by

NewMacHater01

For me, it is not bad when running, but the boot is appalling.
I have a 27" 2019 iMac Pro, with 64GB, and a 4TB SSD. Previously it took about 22 seconds to boot (slightly longer than my 27" I7, fusion), but now it takes over five minutes to boot.
It is the section from about 40% to 50% in the progress bar, it just stops and walks forward at a tiny fraction of a mm/minute.
The I7 conversely only takes perhaps a second longer. It's as if something in the boot doesn't actually like something about the Pro.
Once it has booted it almost works OK. Just a couple of applications with issues.

Posted by

ttelmah

Same here after upgrading to Big Sur, the boot time increased and I regret doing the update. Apps are also taking time to load.
Terminal itself is taking time to open :( . I have imac 21.5, 2019. Apple please do something about this.

Posted by

chsasidhar

Painfully slow boot times since Big Sur Installation.
Mac (Retina 5K, 27-inch, Late 2015)
Once everything everything loads it works fine.

Posted by

saboo

The same problem here!!
After the update to Big Sur my Mac gone So much slower🤯
iMac (Retina 5K, 27-inch, 2017)
Processor 3,5 GHz Quad-Core Intel Core i5
memory 40 GB 2400 MHz DDR4
Graphics Radeon Pro 575 4 GB

It takes such A LOOOONG time to open and be able to work!! It must be an update coming soon i REALLY want to believe !!

Posted by

StefKouf

The same problem wit my iMac 27 2017
After the update to Big Sur my Mac isSo much slower, it is lagging
iMac (Retina 5K, 27-inch, 2017)
Processor 3,4 GHz Quad-Core Intel Core i5
memory 20 GB 2400 MHz DDR4
Graphics Radeon Pro 570 4 GB

Posted by

AdamPL

Same here! Updated to Big Sur yesterday, i have a 2019 IMac and its taking an age to load, the whole thing is shocking!! Reminds me of my old Windows XP.......get it fixed please apple, shocking a release is as bad as this! On the plus can go away and make something to eat when waiting for it...

Posted by

nikkim

I have 2 macs - Macbook Air 2015 and iMac 21.5 4K 2017.

On the Macbook I had so much "others" files that I wasn't able to simply update the system to Big Sur, so I did a clean installation. On the iMac - I did a regular update.

The older and slower Macbook Air performs perfectly with the clean installed Big Sur and the iMac is slow as f***. I have experienced this same problem with the update from mojave to catalina.

So guys, it seems that the better option is to back up your data and just make a clean install. Its not that hard... For me as a software engineer(with all the additional software and sysmem tweeks I need for my job) it took me around 10h straight to get my system as it was.

Sometimes its better to invest some good 10h of installing everything from scratch, rather than loosing time in working on slow computer.

Posted by

innovationsmaker

After a long session this morning with Apple support, they have suggested I switch back to Catalina. The rep said that they were having a lot of problems with Big Sur, and it'd probably be several months before it was working properly.
What I've decided to do is add a small external SSD, and install Catalina onto this, and use this to boot. Then can test at intervals as updates come along for Big Sur, to see if it starts to work acceptably.

Posted by

ttelmah