I have a 2014 27" i7 Retina iMac. It has slowed to the point of being unusable after upgrading to High Sierra. Simply opening Finder takes more than 5 minutes before the files are done displaying and the beachball stops.
Is there anything that I can try before I restore from a backup?
MacBook Pro, Windows 7
High Sierra rendered my 2012 MB Pro nearly useless, while my 2011 iMac with identical i5 CPU, system and applications hummed along smoothly. The problem turns out to be that the OS is optimized for SSD storage, and it will bog down horribly if storage I/O isn't as fast as it expects. I upgraded the MB Pro to an SSD, and the machine instantly became wildly fast and glitch-free. The 4 GB of RAM is more than enough for routine work, w/ MS Office, a browser, and Acrobat reader all in use - probably because caching is so effective with an SSD.
The giveaway was the one difference between the machines: the iMac already had an SSD. The upgrade is a no-brainer at today's prices; my 500 GB SSD was $45 delivered. More effective than a memory upgrade, and cheaper to boot. Just do it, folks.
After upgrading to High Sierra I experienced an extremely slow imac. Turning off iCloud Drive returns the functioning to normal. I will wait for each new update to attempt iCloud Drive again...
Post the Etrecheck report here so we can examine it.
I can confirm Sierra and High Sierra are GARBAGE!!! Using imac 5k i am at my 4th install of OS, I have tested my system with Sierra and HS for so long, I am done with it. Extremly laggy, beachballs, shutdown hangs, slow and skipping mouse pointer of the Logitech Revolution, HORRIBLE support of flash on every video website or website using flash, launchpad unusable - it takes 15 secs to open and SO MANY MORE issues!
All gone now after installing El Capitan with the same software, done by hand, not even restored from TM.
It drove me mental for about a month, I now give up. Its garbage.
I actually recently just finished getting my computer to run fast again finally from using High Sierra.
Unfortunately, the only solution was reinstalling Sierra OS (downgrading) and then reinstalling everything I already had on it.
Works fine again now.
My guess (and recommendation) is 2013 and older Macs should just stay on Sierra, because everyone I've talked to (that actually understands computers) have had issues with anything higher than Sierra on 2013 (and before) Macs.
On the flip side, I've had those same people say High Sierra works great on newer Macs.
macOS High Sierra - Technical Specifications
General Requirements
Mac Hardware Requirements
For details about your Mac model, click the Apple icon at the top left of your screen, choose About This Mac. These Mac models are compatible with macOS High Sierra:
I haven't read all the way back on your problem... a new topic of your own may help, but...
Open Console in Applications>Utilities & see if there are any clues or repeating messages when running.
We know it's slow. Post the results of the Etrecheck run in your reply so we can examine and evaluate it.
Get your hard drive checked by Apple
In my case, there is no rebuildingSSD. I just have to delete the keyChain file to get the laptop to the normal speed. But then I sort of lost all my keychain and have to rebuild it.
I have personally decided to downgrade to Sierra. I used a Time Machine backup for my MacBook Pro to do that and will probably build up my iMac from scratch on Sierra once I am sure I have all my personal data and settings backed up properly.
I experienced a massive slowdown on my model "late 2012" imac after updating to High Sierra. Apple helpline was helpful, we got through all the steps outlined in this thread including reinstalling the OS. This was yesterday. The machine was just as slow. Last night I connected an external harddisc and made a Time Machine backup having neglected to do so since december (three months ago) - I am relying on another in the cloud backup system.
So the big surprise, this morning the machine is running a whole lot faster - especially web browsing is now back to acceptable speeds.
So ... I am not able to conclude anything since I have zero tech insight - but just wanted to share this experience, maybe it can help other users or Apple.
Indeed, but both working perfectly until the update
That's what happens when you put a lot of stress on a failing hard drive. It fails completely.
I'm so fed up at having to shell out cash on a new laptop and desktop, so close together
You could have just put an SSD in each and spent only a couple of hundred.
The settings of encrypting/decrypting data to whatever drive your Mac is using every single time your Mac has to read/write something to the drive IS EXACTLY what is making your Mac run slower.
Unless you work for a security firm or government agency or deal with a type of business where security is a high priority, or you travel with your Macs a lot and/or if you are of a paranoid type/nature, there is really no need to encrypt the data on a computer drive.
There is a substantial negative drive and performance hit by using active data encryption/decryption on a computer’s drive.
Been using Macs for over 20 years.
Never needed or used data encryption on any internal or external drives I have used with my Macs.
Picked up computer with new HD.... working fine with High Sierra. Hoping it stays that way~!
Have you tried the fixed suggested in the earlier part of this topic? Have you run an Etrecheck report? If so post the results here.
iMac Unusably slow after High Sierra Upgrade
