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.
Revert, or get an SSD. Those are the choices. I guarantee you'll be happier with the SSD.
Apple's biggest sin is how hard they make it to upgrade the iMac. You could pop in a SATA drive as easily as you pop in an SD card, but nooooo . . . you have to pull off the glass, remove twenty screws, disconnect tiny, fragile connectors, and pull off the screen before you can get at anything. Or pay $100 to have a technician install a $40 item. That's sh*tty design, no matter how slick they make it look.
Incidentally, and I may have to apologise for coming late to this thread, but what is your activity monitor showing? I have noticed that since the High Sierra upgrade the MDS tasks and the Kernel Tasks have increased the pressure on the CPU. I have an i7, SSD and 16gb RAM but still the fans go mad. The MDS tasks are spotlight indexing and it will take a time to reindex. Once the disks have reindexed the fans should slow down. The kernel tasks usually become active during startup and settle down once everything is chugging along.
I actually did a clean install from a USB install disk last night of High Sierra and (touching wood), all seems to be better.
You can download Sierra from apple's site here: https://support.apple.com/en-us/HT208202
Just scroll down a little bit you will see it. You will need to download it to your machine. However since you have High Sierra installed it won't allow you to install it cause it's an older version. With that said what I did was use DiskMaker X http://diskmakerx.com/whats-this/ use the previous version which it has one for macOS Sierra, OS X El Capitan and Yosemite Compatible. Once you have downloaded Sierra to your system due not install or run it. Just go ahead and create a bootable USB drive with it using DiskMaker. After you can then go about reinstalling it to your system.
So I just took my late 2013 iMac into the store for a diagnostic. They confirmed that the upgrade shot my hard drive. It’s about $199 to replace and he even suggested upgrading to a SSD at an authorized location. I opted to just replace the hard drive with them. Easiest option for me right now. Everything else looks great and he seemed confident that this would be the fix. I’m having them install high Sierra and will test the speed before leaving the store. Will have them install Sierra if I’m not happy with the performance and go from there.
In my case, I updated my MacBook Pro to 10.13.6 and started experiencing slowness to a point that after reboot, the booting seemed to hang in the last 10% of the progress bar.
I tried all the mbr_cache cleaning, remover some Library files, safemode, etc., as mentioned by other users. But none really helped a lot. At the end, in my case, it was caused by corrupted keychain and I have to reset it to get the laptop working normally.
Hi Everybody with High Sierra Upgrades!
I wrote earlier that I have a MacBook Pro Retina 13", Late 2013, 8 GB RAM, Intel Iris graphics, which was VERY slow with High Sierra Upgrade. I tried everything posted here but I still got small improvements. The most annoying was a large lag (seconds) between typing something until the effect appeared on the screen. I thought that before I throw the Pro into trash I have nothing to lose if I upgrade to Mojave. I did this and actually now the computer is very fast and responsive, so I started working with it. I did nothing special except upgrading and the upgrade went smoothly with no incidences. Try the upgrade! Of course I am disappointed that Apple certainly has a bug in High Sierra and it took a lot of my time to try to fix the problem.
Post a report from this please...
EtreCheck is a simple little app to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac.
http://www.etresoft.com/etrecheck
Disconnect all peripherals and then retest, if the performance is still bad then it's likely a hardware problem. The ONLY reliable method of diagnoses is to take it to an Apple Authorized Service Provider that has the correct tools. It's possible one of your peripherals such as your NAS is causing the issue. This is why I am suggesting disconnecting all the peripherals to see what happens.
You seem to have missed what I have written. I have solved my issue by replacing the disk. EtreCheck didn’t work for me. I didn’t have anything causing a problem and my system was still extremely slow even after I formatted the drive and reinstalled the OS. I was suggesting that the poster could create a bootable clone to check his disk.
I have seen this issue crop up with fusion drives and it has to do with the new file format from what I can tell.
In addition the 3 TB fusion drives had a recall REP program from Apple so there may be that going on.
See apples site on the APFS. Prepare for APFS in macOS High Sierra - Apple Support
The upgrade did attempt to make the existing fs/disk into APFS failed and left me with two drives - the hd and the ssd and did not reconnect them as a fusion drive. The newer versions of the upgrader are doing better. From the split point whatever you do format the HD into it will run slow untill you “rebuild” The core storage volume (fusion drives). The option to build the core-storage volume does not exist on the graphical-interface disk utility. Idid try to format the hd both ways - apfs and hpfs+ - and both where slow compared to the fusion-drive. The upgrade at the time I used it did not give you the option of leaving the fs unchanged.
How much RAM installed?
Mac OSes from OS X Yosemite and later really need a base amount of RAM of 8 GBs, now, and even more RAM than this is better IF your Mac’s GPU is the type of integrated ( NOT discreet ) GPU that shares the physical RAM in your Mac for VRAM and for the OS together.
When this happens, Mac OS performance can vary based on how much available RAM has been used by the OS and for the GPU.
I could not get the system to allow me to uncheck the Desktop & Documents Folders option. However, I logged out of my icloud account and the system is now usable. I'm going to try to upgrade to Mohave to see if I can then use my icloud account. I'll report back.
Make sure you format the drive as os extended and not APFS because it does not support fusion drives yet.
If your drive is APFS format then try to backup and reformat the drive to OS extended journaled.
iMac Unusably slow after High Sierra Upgrade
