iMac running WAY slow! New computer or increase memory?

Hey there Jim Alden,

Thanks for reaching out to Apple Support Communities. I understand you’re experiencing some performance issues your Mac. I’ll be happy to help.

If you’re having performance or stability issues, these solutions might resolve the issue.

First, check your hard drive space and see if at least 15% of your storage space is available. This can have an affect on performance: 

How to free up storage space on your Mac

Perform an SMC and NVRAM reset on your Mac:

How to reset the System Management Controller (SMC) on your Mac

Reset NVRAM or PRAM on your Mac

Boot into safe mode to isolate the cause of the issues or even resolve them:

Use safe mode to isolate issues with your Mac

Use Activity Monitor to help you identify what could be cause the performance issues:

See how apps affect Mac performance, battery runtime, temperature, and fan activity

As far as updating your RAM, please see the following:

"Memory is not removable by users on iMac (21.5-inch, Late 2012), iMac (21.5-inch, Late 2013), iMac (21.5-inch, Mid 2014), iMac (21.5-inch, 2017), iMac (Retina 4K, 21.5-inch, 2017), and iMac (Retina 4K, 21.5-inch, 2019). If the memory in one of these computers needs repair service, contact an Apple Retail Store or Apple Authorized Service Provider. If you’d like to upgrade the memory in one of these models, an Apple Authorized Service Provider can help. Before you schedule an appointment, confirm that the specific Apple Authorized Service Provider offers memory upgrade services."

Install memory in an iMac

Cheers 

I have the exact same system and plan on upgrading both memory and to replace the slow platter drive to a 1tb ssd . Parts to do both comes out to $89 for the memory and $125 for a 1tb ssd . There a few videos out the to show to replace both . It’s not for the faint of heart but doable with a lot of patience and watching the videos ..

the $89 price for memory includes the need tools

r

Jim Alden wrote:

So what about doing a clean install of Mac OS Catalina to clean out old files that might be slowing down my computer?

That is always an option, but you have to be careful about migrating the problem back. If you do the clean install you should only migrate your user account back and manually reinstall your apps. Just make sure to have good verified working backups of your data first. When erasing the drive you want to make sure to select the physical drive ("Apple HDD HTS54...") as GUID partition and APFS (the first option).

Before doing the clean install try removing the two items I mentioned before. Also run DriveDX to check the health of your hard drive and post the report here using the "Additional Text" icon which looks like a piece of paper. Post the report even if the drive appears healthy as the report may contain a valuable clue.

The Load Cycle Count can cause those issues when it gets too high (usually the lifetime RAW value is somewhere between 600k and 900k). The Load Cycle Count doesn't trigger a drive failure since it is only an "old age" indicator, but since this indicator is at the end of its expected life (or even beyond it) and you are having performance issues, then it indicates the drive should be replaced. I would suggest replacing the hard drive with an SSD. Some iMacs need a special temperature sensor adapter cable when using a third party drive or the fans will run at high speed. I don't recall if your iMac needs this temp sensor or not. A Crucial MX500 or OWC SSD are two recommended options. Don't use the Crucial BX500 as it can be an extremely slow drive.

DriveDX and other similar apps may not always accurately report the health of an SSD. These apps are useful in viewing the SMART attributes (aka "Health Indicators") so a knowledge user can interpret the health of an SSD and for running the SSD's internal selftests.

Jim Alden wrote:

Here is my Etrecheck report.

<Etrecheck report.log>

The Western Digital proprietary software for your external drive could cause system issues. You do not need to use the WD software to manage your external drive. It is better to just let macOS manage the external drives.

I don't know anything about the SplashTop Streamer software so this could be another item causing your issues.

You can run EtreCheck to check for any software issues which could affect system performance. Post the report here using the "Additional Text" icon which looks like a piece of paper.

Try running the Apple Diagnostics.

If the diagnostic doesn't find a problem, then you can also check the health of the hard drive by running DriveDX. Even if the drive appears healthy, post the DriveDX report here using the "Additional Text" icon which looks like a piece of paper. The report may contain clues about the condition of the drive which could slow your system.

Jim Alden wrote:

Thanks for all the tips. I will definitely try some of these things. I wanted to tell you two things I have noticed. In activity monitor, when I look at my memory, out of my 8 GB of physical memory, 3.7 GB is cached files. I followed the instructions in some articles about how to empty out these cached files, but after restarting it looks like I still have the same amount of memory being used for those files.

Don't worry about it as long as the memory pressure stays in the green and you do not use GBs of Swap or Compressed memory. If you reboot the computer make sure to uncheck "Reopen all windows" on the shutdown prompt, then your memory use at next login should be minimal. macOS always has memory cached since unused memory is wasted memory.

Also, when I click on the icon for my hard drive, and then hit get info, out of my 540.3 GB of available space, it’s saying that 56.23 GB is purgeable. What does that mean and how do I get that space back?

Don't worry about purgeable items. macOS will handle it automatically. See this article describing purgeable items:

https://blog.macsales.com/39247-rocket-yard-guide-what-is-purgeable-space-in-macos/

Jim Alden wrote:

So another outcome last night. My iMac is set up for two users, so when I ran Etrecheck under my user name as well as Apple Diagnostic, no problems were found. But then when I ran Etrecheck under my partners user name, The report came back that I may have a failing hard drive.

Maybe something in your partner's user account slowed down the system so EtreCheck thought the drive was failing. Or maybe the drive is failing. Run DriveDX and post the report here even if DriveDX shows the drive as healthy since the report may contain useful information.

also, I started up from recovery disk and ran disk utility, and I saw a couple things that were confusing. First of all, it looks like my drive is divided up into five sections or images? I know Catalina sets aside a certain section for files that users cannot alter, so does that mean each user has a user section and a data section?

High Sierra and Mojave have multiple APFS volumes for system use and Catalina adds yet another volume to separate the core macOS system from the user data.

finally, I noticed that the formatting of my back up drive is the older format of HPFS. Does that matter? I did get rid of the WD and Splashtop software.

HFS+ is Ok for Mojave and earlier, but Mojave defaults to APFS. Catalina requires an APFS volume. Some users on these forums have been reporting that the Catalina installer isn't converting a Mojave HFS+ installation to APFS so the Catalina installer fails.

wow this is confusing.

Yeah, Apple has been making things much more difficult and confusing.

has to be 2.5 inch ssd drive .

yes there is a fear of breaking the glass but OWC sells the right tools and they have an excellent video on the process