iMac slows down after Big Sur installing

App & System Services Core OS macOS

Created Jun ’20

Replies 180

Boosts 0

Views 63k

Participants 168

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

Boost

hellogator OP

Dec ’20

I have a Mid 2015 MacBook Pro with 1TB SSD and the fan starts spinning a few minutes after booting, then the system crawls after about an hour of so, especially when left idle. What's frustrating is that the slowness always occurs, even if I don't open any apps.

MacBrick "Pro"

captTuttle76 OP

Dec ’20

This is utterly insane--the drastic reduction in speed. I have learned a very valuable lesson with these updates. Wait a while. Wait a good long while. Hopefully Apple will announce they're looking into it and/or addressing the situation.

Capitan_Kakao OP

Dec ’20

I feel that my MacBook Air (Intel 2020) became significantly slower with increased battery drain. Should we all sign the collective complaint or something?

RaeanneP OP

Dec ’20

I also have a Retina 4K, 21.5-inch 2017 and am extremely frustrated with how slow this is running. The lack of speed has become very problematic! Slow to wake up and load apps, black screen, etc. I never had this problem with previous operating systems. Please fix soon!

avloss OP

Dec ’20

iMac (Retina 5K, 27-inch, 2019)
3 GHz 6-Core Intel Core i5
48 GB 2667 MHz DDR4

Updated to Big Sur the other day - computer is borderline unusable now. Delays are everywhere - typing, moving windows, opening programs. GIMP-2.10 became practically unusable, with insane delays for even most basic actions (not that I really care much about GIMP, but it used to work just fine, and now it doesn't, and delays are most obvious in that program). I regret updating so much.

lazyzeroed OP

Dec ’20

iMac (Retina 4K, 21.5-inch, 2019)
3,2GHz 6-Core i7
32GB DDR4

My iMac worked fine after the first reboot, except that I could not watch anything on Netflix or on any other streaming service anymore (the screen just went blank after a few seconds, but the sound was still working), but it works with Chrome.
And after today's boot it's SO damn slow! It took several minutes until I could open any apps and Safari crashed multiple times.
Fix this, Apple!!

sverroc OP

Dec ’20

27” IMAC 2017 is having same problem after installing Big Sur OS. Very slow operating and high level of frustration in waiting for the computer to respond. Spent 2 days on the phone with Apple Support without resolution. Last thing done was to reinstall Big Sur OS. This was done twice and did not resolve problem. Now Apple Support is recommending to back-up drive so it can be wiped clean and start over. Big lesson learned, I did not backup computer before the first download of Big Sur OS. Now they say there is no going back.

frz OP

Dec ’20

Same here - my iMac – 2019 / 3,8 Ghz / 16 GB Ram – is practically unusable.

seanmccallan OP

Dec ’20

Same with my MacBook Pro 2019 Retina. Catalina was perfectly fine but Big Sur has ruined the experience. Pretty much every aspects feels slow and janky, and I'm unsure about the mobile-device feel of Big Sur - would revert to Catalina if it was quicker and easier to do so.

adrianursocool OP

Dec ’20

Same here with my Macbook Pro – 2018 / i7 2,9 Ghz / 16 Go Ram / SSD 500Gb...

RedRaymond OP

Dec ’20

Bottom Line: Big Sur is a Disaster! Like many people, if this isn't fixed fast, my Mac days are over!

Grt2fly OP

Dec ’20

Upgrading to Big Sur has been a disaster - as others have noted my MacBook has become a jittery, slow response frustrating experience. Apple - you guys better get this figured out quick ! Its ridiculous.

vxx OP

Dec ’20

MacBook Pro (15-inch, 2017) 16GB RAM with 2,9 GHz Quad-Core Intel Core i7
The window animation is terrible (when opening preview of images/videos/etc), minimizing, maximizing, even when scrolling pages in Chrome, but in Safari is fine. All my apps are up to date.
It's like is running with 5fps!

AndrewCali OP

Dec ’20

Hello, I'm having the same issue with my notes and reminders app lagging with the new Big Sur update on my 2017 MacBook Pro. It's extremely frustrating and make the apps unusable. It's also worth mentioning that the notes and reminders apps also lag on my new 2020 iPad Pro. This is an urgent and important issue that the development team needs to prioritize.

Curvestone OP

Dec ’20

Dear Apple developers,
after downloading Big Sur to my iMac (Retina 5k, 2017, 4,2 ghz quad_core, intel I7) the performance became terribly slow. I am working as professional photographer and photo editor and this upgrade is a disaster in regard to the speed of starting up and performance in general. Under Catalina my processing workflow was fully satisfying, in speed and switching between the several software packages which I am simultaneously running (Adobe Photoshop, Lightroom, ON1, NIK, etc).
Please fix it!