iMac 18,3 running very slow

Hello!

Thanks for providing an EtreCheck report!

Unsigned files - There are unsigned software files installed that could be malicious and should be reviewed.

Run Malwarebytes, since I see you have that installed.

Automatic updates disabled - Automatic updates are disabled. This computer is at risk of malware infection.

Security updates disabled - Security updates are disabled. This computer is at risk of malware infection.

Apple security disabled - Apple security software is disabled. This computer is at risk of malware infection.

It appears that your Security and Updates are disabled. Please go to System Preferences > Software Update, and turn on the following:

• Check for Updates
• Download new updates when available
• Install App Updates from the App Store (optional)
• Install System data files and security updates

Then, go to System Preferences > Security & Privacy > General, and make sure the "Allow Apps downloaded from" is set to either "App Store" or "App Store and Identified Developers" (those may be the only options shown).

More than one antivirus app - This computer has multiple antivirus apps installed.

Mac computers do not need any sort of anti-virus software. Anti-virus can cause performance issues, security issues, and make macOS appear buggy. Your Mac is worse with these types of Apps installed.

In addition, Mac computers cannot get any traditional "viruses". They only area of concern is some malware, mostly adware, and it's easily avoidable. Do not install apps from unknown sources, and you'll be safe.

Here are some links that describe Apple's built-in malware protection, which are far superior:

•  macOS - Security - Apple
• Protecting against malware in macOS - Apple Support

Delete CleanMyMac and SafeNet following the developers instructions.

The only app you might ever need is Malwarebytes to remove an existing infection.

No Time Machine backup - Time Machine backup not found.

Make sure you have a backup of your Mac. Having a backup ensures your data is protected from accidental deletion and when something goes wrong. 

With Time Machine, you can easily create a backup of the files on your Mac. To start your first Time Machine backup, you need an external hard disk. If you don't already have one, these specific external hard disks, sold by Apple, are excellent options and compatible with Time Machine:

• LaCie 2TB Mobile Drive External Hard Drive USB-C - Apple
• LaCie 2TB Rugged USB-C Portable Hard Drive - Apple

You can then Back up your Mac with Time Machine - Apple Support.

Additionally, you can use iCloud to also backup your Mac. iCloud can act as an off-site backup, but iCloud should be used in addition to Time Machine. Here are some resources on setting up iCloud for Mac:

• Upgrade to iCloud+ - Apple Support
• Set up iCloud Drive - Apple Support
• Add your Desktop and Documents files to iCloud Drive - Apple Support
• Set up and use iCloud Photos - Apple Support

After you setup iCloud, turn off Optimize Mac Storage in System Preferences > Apple ID. That way, all changes made to files in iCloud are also backed up to Time Machine.

Heavy RAM usage - Apps are using a large amount of RAM.

Is there a reason you're using Google Chrome? Google Chrome uses a large amount of Memory. Safari is safer, faster, and far more Memory efficient.

Additionally, you should restart your Mac. Restarting should clear out some Memory.

Runaway user process - A user process is using a large percentage of your CPU.

For some reason, Malwarebytes is using a large percentage of your CPU. Is the Malwarebytes app up-to-date?

Performance:

System Load: 2.74 (1 min ago) 2.56 (5 min ago) 2.57 (15 min ago)

Nominal I/O usage: 4.98 MB/s

File system: 25.95 seconds

Write speed: 208 MB/s

Read speed: 1275 MB/s

I am concerned about your Fusion Drive performance. Please run and upload a DriveDx health report for both your hard disk and SSD that make up your Fusion Drive:

How to use DriveDx - Apple Community

We can then see if your disk(s) are failing, or if your Fusion Drive is slow due to all the software issues listed above.

Finally, startup in Safe Mode after doing all the above, restart into normal mode, and upload a new EtreCheck report.

Moving forward, if after addressing all the issues, and performance still suffers (assuming your Fusion Drive isn't failing), you'll probably need to perform a full erase of your startup disk and reinstall macOS.

Jack

Jack had many good suggestions.

Note with your fusion drive

Drives:

disk0 - APPLE HDD ST1000DM003 1.00 TB (Mechanical - 7200 RPM)

Internal SATA 6 Gigabit Serial ATA

disk1 - APPLE SSD SM0032L 28.00 GB (Solid State - TRIM: Yes)

Internal PCI-Express 8.0 GT/s x2 NVM Express

disk1s1 - EFI [EFI] 315 MB

disk1s2 [APFS Fusion Drive] 27.69 GB

It is almost entirely a mechanical drive, those are very slow under APFS. Also, your drive has only 5% free space (50 GB out of 1000 GB), you should keep 15%-20% free space.

Mount point: /System/Volumes/Data

Fusion drive

Used: 957.86 GB

Shared values

Size: 1.03 TB

Free: 45.00 GB

Available: 55.02 GB

Not only is the mechanical drive very slow under APFS, there is not enough room for virtual memory and paging, that can bring a Mac to a standstill.

Jack's suggestion about checking the drive with DriveDX is also good because the fusion drives have a mixed record on longevity and yours is more than 5 years old. DriveDX checks the hardware condition via the SMART parameters. You should run the LONG (extended) test. As Jack pointed, there could be multiple things going on, maybe hardware issues, plus CleanMyMac (never good to have that installed). Malwarebytes is a good tool but some have reported that have it always checking automatically in the background slows their computers down, so turn that feature off.

For why APFS runs so poorly on mechanical (or fusion) drives, see:

https://bombich.com/blog/2019/09/12/analysis-apfs-enumeration-performance-on-rotational-hard-drives

https://eshop.macsales.com/blog/43043-using-apfs-on-hdds-and-why-you-might-not-want-to/

Antivirus software: SafeNet, CleanMyMac, and Malwarebytes

I would uninstall SafeNet and CleanMyMac, completely uninstall using vendor's uninstaller. These types software have been known to cause slowdowns. For Malwarebytes, that one is ok but try turning off the automatic protection that runs all the time in the background.

Run the DriveDX LONG test. I have a Mac that fails the long test but passes the short test. Just in case. The short test results look ok for your drive.

If all the above don't help, I would suspect the slow fusion drive. It is almost entirely a mechanical drive except for a tiny piece that is an SSD. See these articles about mechanical drives and APFS:

https://bombich.com/blog/2019/09/12/analysis-apfs-enumeration-performance-on-rotational-hard-drives

https://eshop.macsales.com/blog/43043-using-apfs-on-hdds-and-why-you-might-not-want-to/

If this is the reason, upgrading RAM will not help, I think you have plenty of RAM. If the mechanical drive is slowing your machine, replacing it with an SSD (or switching to an external SSD boot drive would be the solution.

+1 to Steve.

It doesn't appear you've deleted the anti-virus, enabled Apple Security, created a Time Machine backup, or stopped using Chrome (a HUGE performance hog):

Top Processes Snapshot by Memory:

Process (count) RAM usage (Source - Location)

Google Chrome Helper (Renderer) (24) 2.30 GB (Google LLC)

Please try to follow the steps suggested above. The good news is your Fusion Drive is in good health. However, you can always run the full-test on your hard disk as Steve suggested if you have time.

If after cleaning up your Mac (steps above), you still suffer from poor performance, the next steps to look at are performing an erase and reinstall of macOS.

Jack