iMac 27-inch 2019 with internal SSD is very slow

In general your report doesn't look to bad.

1) You are running a lot of third-party App's on only 8G of RAM.

2) The iMac has not been restarted for 30 days.

At this point, I recommend that you:

1) Run less third-party app's at the same time.

2) Restart more often to free up RAM and clear the Swap Used.

Or optionally:

3) Upgrade the RAM by adding a couple of 8GB modules in the empty slots.

https://eshop.macsales.com/shop/memory/imac-2019-27-inch

Install memory in an iMac - Apple Support

4) Consider replacing that older Intel iMac with a new iMac or a new Mac mini and external display.

Mac - Which Mac is best for me? - Apple

EtreCheckPro is an excellent tool to help sort out slowness and other problems.

Download and run the free version of EtreCheckPro, from > https://etrecheck.com/en/index.html

Then post back here with your Report, as per > How to use the Add Text Feature When Post… - Apple Community

I suspect the Hard Drive portion of the Fusion Drive may be failing. Run the third party app DriveDx (free trial period) to check the health of the Hard Drive. 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'm not a macOS software expert, so I will leave the software analysis to the other contributors, but I would hold off until we know the health of the Hard Drive. May as well post the report for the internal SSD portion of the Fusion Drive as well.

That is the same Drive DX screenshot of the SSD, that you posted back on Feb 12 2026.

Please post a Drive DX report for the APPLE HDD ST1000DM003 1.00 TB (Mechanical - 7200 RPM)

One other thing that I just noticed in that Feb 12th Drive DX report.

Is that the iMac had still not been restarted in nearly 32 days after a restart was suggested back on Feb 11th.

What type of ssd?

NVMe, SATA

FUSION (ssd/hdd hybrid)

i would run. macOS DriveDX app

for drive health - it will also note the type(s) of internal drives

I agree with den.then that you need additional RAM, either a total of 16 or 24 GB (i.e. two 4 GB modules or two 8 modules from OWC - MacSales.com).

Be sure to remove all of the items in the Cleanup section of the report. There's a lot of flotsam in there that can be removed.

If you consider getting a new Mac in the near future consider the following; a 10 Core Mac Mini M4 with 16 GB RAM and 1 TB SSD ($1084 US) with a 32" LG 4k monitor ($331 US) from Amazon.com)  is $1415 US which is $541US less than a similarly configured new 24" iMac ($1956 US)  re 07/2025. Keep your keyboard and mouse from your current Mac for use with the Mini. 

I got the above Mini with a 32" LG 4K monitor w/speakers for only $60 US more than the 27" (didn't know the Mini had a speaker).  There are many monitors available in 27" size for $100 US to $500 US depending on what features you want.  The monitor prices are before tariffs.

Just some food for thought.

Seattle Jeff wrote:

Yes, I have been avoiding restarting because 1) it takes forever 2) apps take hours to load back up

It is true that a Fusion Drive system takes somewhat longer to startup than an SSD system.

If you want to improve that iMac's Startup/Restart time.

Remove some or all of the Apps and Extensions that are opening at login.

see > Remove login items to resolve startup problems on your Mac - Apple Support

I'll go ahead and restart more often. And I'm exploring the additional RAM.

That and/or more RAM is needed to smoothly run everything that you are running on that Mac.

- it has prohibited me from getting important work done.

Then it is time to seriously consider replacing that 7 year old Fusion Drive iMac with something newer.

see > Mac - Which Mac is best for me? - Apple

The 28GB SSD looks OK.

What does Drive DX say about the iMac's 1T mechanical hard drive..?

Seattle Jeff wrote:

Hi Den. Yes, I have been avoiding restarting because 1)it takes forever and 2) apps take hours to load back up - it has prohibited me from getting important work done. I'll go ahead and restart more often. And I'm exploring the additional RAM. As for running Drive DX on the 1 TB drive, I've pasted it below. Thank you.

<Drive DX Report on the 1.0 TB drive.log>

I don't see anything concerning with the health of the internal Apple Hard Drive. At least none of the usual health attributes I monitor show anything concerning. I don't monitor some of the health attributes because no one knows how they behave or should be interpreted. Some drive related issues may not be monitored such as the drive's own controller.