Slow iMac 2017

Download and run Etrecheck. Be sure to give it Full Disk access before running.

Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Copy the report

and use the Additional Text button to paste the report in your reply.

Then we can evaluate the report to see if we can determine the cause of the problem.

First you should be aware that at the time of purchase you purchased the slowest iMac that Apple offered at the time: 8 GB RAM and a 5400 rpm hard drive.

Besides the network proxies unless you're using a true VPN tunnel, such as between you and your employer's, school's or bank's servers, they provide false security from a privacy standpoint.  Read these two articles: Public VPN's are anything but private and Former Malware Distributor Kape Technologies Now Owns a Number of Public VPNs and a Collection of VPN “Review” Websites.  

Uninstall the TotalVPN according to the developer's instructions.

Flip4Mac hasn't been needed by Macs for several systems. I'd remove it.

Your read and write speeds are abmisal, Write speed: 44 MB/s, Read speed: 48 MB/s.

You could improve that by about 10x or more by getting an external SSD, cloning your boot drive to it with Carbon Copy Cloner and booting and running from there.

This is what I get for speeds with a non-optimal external SSD setup with the same model iMac:

I recommend drives from OWC (MacSales.com) as they have proven reliability, excellent customer support and warranties. 

For your model contact OWC's customer support and get their recommendation for the SSD model that would be most optimal and best suited your iMac model, work requirements and budget.  They may have additional models other than those I've shown above.

I agree that 95% of any "slow" issues are due to the entry-level hard drive Apple used in 2012-2019 21.5-inch iMacs. You have exactly that drive, and it is running at half its normal slow speed of 70-80MB/sec. The external USB3 SSD drive option already mentioned is the most cost-effective way to improve performance.

It is not the processor nor the RAM. My daughter has the same machine and specs as yours but it was ordered with Apple's internal SSD option. It is as fast as stink.

There are a few minor things to consider:

1) Client-side VPNs are of questionable benefit at best and can slow performance.

2) There is some evidence that old versions of DivX can slow performance, and I found a DivX component that is older than your computer:

[Loaded] com.divx.agent.postinstall.plist (Not signed - installed 2012-03-16)

Other DivX components are from 2018.

👉🏻Apply Rule 125544-22 rev D : "If you use it, update it. If not, dump it."

3) Consider testing with the WD external drive disconnected. If you have a Photoshop scratch disk there, that will slow PS. The WD Elements is old and connecting at USB2 rates (480MB/sec). Your iMac has USB 3 ports rated at 5000MB/sec and ever faster ThunderBolt ports.

Proxies - Network proxies detected. This could be evidence of malware.

System Preferences>Network>choose interface>Advanced>Proxies Tab, make sure none are set, like for HTTP & HTTPS, unless you know they're needed.

disk0 - APPLE HDD HTS541010A9E632 1.00 TB (Mechanical - 5400 RPM)

The slowest possible HDD.

This computer may have configuration profiles installed.

Is this a work or school owned computer?

Yes the easiest & fastest so far would be what I use, The Envoy Pro FX...

https://eshop.macsales.com/shop/owc-envoy-pro-fx

But there ae other TB3 drives cheaper & all would bury that internal drive.

Give etrecheck Full Disk Access before running it...

How to use etrecheck…

Using EtreCheck - Apple Community

Using EtreCheck - Apple Community

Many of us will be happy to look over the EtreCheck report.

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