2015 iMac 21.5” Desktop Running Slow/Unresponsive

Yeah, this is the 8 GB hard disk drive (HDD) configuration. It’s the same iMac model mentioned my previous link.

See the article for options to improve performance prior to replacement, too; for installing and loading and booting from an external SSD. Which will be somewhat faster than that HDD, and for reasons described in the linked article.

Additionally, and to reduce the load here, consider removing Nord, DDG, VirtualBox, Google apps, and anything else you absolutely don’t immediately need.

This iMac is immensely under-configured or immensely overloaded, or both.

Good job getting the EtreCheck report posted.

To start, it's immediately evident that the Mac is performing poorly. Typically a report can be generated within about three minutes. Yours took over thirteen! (13:29)

Your Mac is of a generation when Apple was configuring them with a slow 5400 RPM HDD. This is a common performance bottleneck. The drive also is formatted with APFS, which is great for SSDs, but create another potential bottleneck because of the data transfer overhead required. APFS creates more work for an HDD.

Finally, couple those with only 8 MB RAM and this Mac was never a speed demon.

Still, it should perform better than it is. Unfortunately, to run macOS 12 Monterey, the drive must be APFS formatted. You're in a catch-22.

It appears that you have NordVPN installed and also may have DuckDuckGo VPN enabled. VPNs may not provide the level of security that they proffer and are in a group of apps that may hinder the performance of macOS and your computer. These problematic apps are VPNs, anti-virus, cleaning, optimizing and security software. They don't provide any function that macOS cannot or does not itself provide, so they aren't needed. These are best removed and left uninstalled.

• Security Risks: The Dangers of Using Free VPNs – eccu.edu.  

Your drive performance is extremely poor:

Performance:

Write speed: 65 MB/s

Read speed: 58 MB/s

This suggests to me that you may have a failing drive. These should be in the 100-200 MB/s range.

I suggest you run diagnostics on the drive to assess its overall health. The DriveDx app from Binary Fruit is often recommended as a useful tool and I believe they have a free evaluation period.

If the health of the drive is determined to be an issue, your option are to install macOS on an external drive and run the Mac from that, or you might consider replacing the internal drive with another, perhaps an SSD. The latter may well be less cost effective than running from an external drive. How to use an external storage device as a Mac startup disk - Apple Support

These are the things that jump out at me to be addressed. Others may find additional items to consider.

The eleven year old 2015 iMac is considered obsolete by Apple standards. You can address the HDD problem as I suggested if you wish, but I believe it would be wise to consider making plans to replace this hardware with something newer. In my experience, the typical lifespan of any Mac is 10-12 years. Yours is right in that window.

MrHoffman wrote:

PS: If a failing hard disk is suspected, the priority ahead of any and all other tasks is to create a complete and current backup, if an existing and recent backup is not already available.

I personally would always suspect a worn out or failing Hard Drive. It is always one of the first things I check regardless of the problem being reported.

The OP can run the third party app DriveDx (free trial period) and post the complete DriveDx text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar. I am more than happy to review the report.

It appears that you may have tried to add an EtreCheck report to your post. Unfortunately that did not post. If you have an EtreCheck report to share so we can look for clues about the poor performance of your Mac, add it to the thread by using the "Add Text" button at the bottom your your next reply.

Please note you must upload the full report. To see how, please click >  How to use Add Text when posting… EtreCheck Report.

EtreCheck is a safe and highly regarded utility from a trusted developer and respected ASC contributor.

We’ll use your EtreCheck report to look for clues to what may be causing your problem and advise how to correct it.

Please navigate to EtreCheck.com to download the app.

Some background on a common iMac 21.5” (8 GB with HDD) configuration, its expected slowness, why it is slow, and some potential performance-improving hardware options not involving replacement:

• Why is my hard disk drive iMac so slow? - Apple Community

PS: If a failing hard disk is suspected, the priority ahead of any and all other tasks is to create a complete and current backup, if an existing and recent backup is not already available.

MrHoffman wrote:

PS: If a failing hard disk is suspected, the priority ahead of any and all other tasks is to create a complete and current backup, if an existing and recent backup is not already available.

Yep. Good point! 👍🏽

HWTech wrote:

MrHoffman wrote:

PS: If a failing hard disk is suspected, the priority ahead of any and all other tasks is to create a complete and current backup, if an existing and recent backup is not already available.

I personally would always suspect a worn out or failing Hard Drive. It is always one of the first things I check regardless of the problem being reported.

Noob. 😉. I suspect everything is always about to fail, new or old, always, with the likelihood of failure determined by the increasing distance from the last full backup or by the decreasing distance to the next critical deadline, whichever causes the most chaos.