From start-up iMac takes time before anything is accessible

First, there is Kaspersky installed. Your Mac does not need antivirus, try and delete Kaspersky and try again to see if the Mac is still slow

Running antivirus on the Mac causes slow performance. macOS has built in security

You're ruing far too much for only 8 GB RAM & a spinning HDD.

Can you disable One Drive for a test?

Can you disable Kaspersky for a test?

You can use Drive DX to possibly get a better view of Drive health…

https://binaryfruit.com/drivedx

And not to beat a dead horse, but Anti Virus Apps all work fine to start with, but most will eventually cause problems due to changes or additions of Software. :)

Hey there!

To begin, I'd suggest that you remove the Kaspersky software:

How to uninstall Kaspersky Internet Security for Mac.

Next, it appears that your Fusion Drive may be failing:

Performance:

Write speed: 59 MB/s

Read speed: 122 MB/s

Most Fusion Drives perform around 600MB/s for write and over 1,000MB/s for read. Be sure to follow BDAqua's advise to check the health of the drive using DriveDx:

DriveDx.

Let us know what DriveDX reports.

Hope this helps!

-Jack

Can you confirm something? In the secondDriveX run, did this general area of the second report:

clearly show a device description similar to this part in the EtreCheck report:

APPLE HDD ST1000DM003 1.00 TB (Mechanical - 7200 RPM)

Internal SATA 6 Gigabit Serial ATA

showing a 1TB mech drive? Code "ST" would be a Seagate drive, and it is the mechanical portion of Apple Fusion. Two physically separate drives—one solid-state and one mechanical—linked by software

I ask because the drive speed scores Etrecheck is reporting—and I've used it enough to trust it—clearly show a devastating storage issue. I do not know why DriveX would not report a problem given how really bad those scores are. Even the known software interferences othrs have identified should not drag the storage speeds to Death's Door, which is where it is based on the firstEtreCheck report.

So can we have another Etrecheck run to see if scores changed after evicting Kaspersky?

On the software side, the issues with OneDrive and Kaspersky are blatant here:

Top Processes Snapshot by CPU:

Process (count) CPU (Source - Location)

OneDrive (2) 95.22 % (Microsoft Corporation) ⚠️

Finder 47.78 % (Apple)

kavd 36.12 % (Kaspersky Lab Switzerland GmbH) ⚠️

fileproviderd 15.68 % (Apple)

EtreCheckPro 13.78 % (Etresoft, Inc.)

and either may be causing the higher atypical CPU usage for Finder. You may be trying to back up too much to OneDrive.

I've collected EtreCheck drive scores from reports here for a long time, and other 27-inch iMacs with the same drive configuration as yours are doing Writes between 600 and 900MB/sec and Reads up to 2000. That as much as 15X faster than your first EtreCheck run.

Long shot: You can use this article to see if your Fusion system has "split." Splitting will cause slowdowns aproaching the level yours is reporting.

How to fix a split Fusion Drive - Apple Support

but EtreCheck's listing of your drives suggests to me it is not split..

Also test with any external drive disconnected to see if Fusion drive performance improves.

As for Kaspersky, web search "Kaspersky banned" and you will get an eyeful. Reports of action are as recent as last month:

www.cnn.com › 2024/04/09 › politicsKaspersky: Biden administration preparing to prevent ... - CNN

It appears that your Fusion Drive is operating much faster after removing the Kaspersky software:

Performance:

Write speed: 554 MB/s (was 59MB/s)

Read speed: 1459 MB/s (was 122/MB/s)

How is the overall responsiveness of your Mac now? Does it feel faster?

-Jack

That 1 TB Fusion Drive only has a mere 32 GB of fast SSD space – compared to the 128 GB of fast SSD space that Apple shipped with 1 TB Fusion Drives prior to Late 2015. It's prime real estate, but there isn't enough of it.

This may account for some of your woes – although things like up to 10 minutes startup times, followed by another 2 minutes of the spinning wheel, would not be normal even for a mechanical hard drive.

If you get the other causes of slowness sorted out, and still want to speed things up, you could consider getting an external SSD and making it your startup drive. Your iMac has both USB-A (USB 3.0) and USB-C (USB 3.1 Gen 2, Thunderbolt 3) ports, which would let you connect to a wide range of modern external SSDs.

You read it correctly.:)

I don't see a report on the main drive, just Volumes : Macintosh HD

Device Path : /dev/disk1

Total Capacity : 28.0 GB (28,000,002,048 Bytes)

But, I think your Fusion drive has split or the HDD part has died...

Volumes : Macintosh HD

Device Path : /dev/disk1

Total Capacity : 28.0 GB (28,000,002,048 Bytes)

Model Family : Apple/Samsung NVMe L-series SSD

Here's how my iMac 19,2 shows...

In Disk Utility>View, select Show all Devices, highlight the top left entry, what shows???

Then you can click the ones under that to see the total size...

But in Disk Utility, what does the Fusion drive or top left one say?