Is my Imac worth saving?

Herbcorgis wrote:

I have a late-2015 Imac.

I got this far after reading the title and thought “nope”

Get a backup, if you don’t already have one. Now. That’s your highest priority task here. Preserve your data.

My original question was going to be advice on selecting an external SSD drive in hopes of speeding it up. It is very, very slow in almost everything it does! To that end, I ran an EtreCheck scan, which didn't flag any major issues. Then I went in and deleted a few things and ran another check. This time, it identified a failing hard drive. I've attached both reports.

Should I try an external drive and, if so, can anyone recommend one? Or is it time to retire this one and move on to a Mini? I'd hoped to be able to limp along until next summer when I understand there will be a Mini update. Any thoughts on this as well? Thanks for the help; I need all I can get!

<EtreCheck Report No. 1.log>

<Etre Check Report No. 2.log>

Ignoring the failing hard disk drive, here is why this iMac is slow:

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

The usual speed-up for a slow iMac will also indirectly resolve the failing hard disk:

Use an external SSD as your startup disk … - Apple Community

If you want to defer a replacement until some unannounced future Mac becomes available, the SSD will probably get you there.

OWC has a good reputation for add-on available storage. Any SSD will be faster than that HDD, too.

That iMac has the older USB-A connections, so you’ll probably want to use an adapter to get to the newer USB-C connection common on newer SSDs, and not purchase a USB-A SSD.

PS: As you are clearly purchasing and keeping your equipment for a long time, I would suggest avoiding purchasing the bottom-tier configurations sold by Apple. Mid-tier performance usually holds up a little better. I’d not go below 16 GB memory with any Apple silicon Mac, for instance.

To be 100% honest, if it were a 27" I would have said it was possibly worth saving due to the 27" display, however a 21.5" is not of the same caliber.

However before you read on, please stop using the computer ASAP as your HD is failing and you do not appear to have any backup!!!! This means when the drive fails you will have permanently lost all the data stored on the HD!!!!!!!!!!! Please buy yourself an external HD today and backup using Time Machine. If somehow you are not familiar with Time Machine please click Back up your Mac with Time Machine.

Also, the computer has not been restarted in weeks, it should be restarted about 1x per week. While not critical this will ensure it has maintenance done on the system that is done in the background. It will also clear RAM use and may speed up the computer a small bit.

IMHO considering it is now 10 years old and was a base model iMac to begin with, I strongly recommend replacing it.

Yes, you can certainly install an external drive, install the operating system on it and designate it as your startup drive. Purchase an SSD drive and not a mechanical drive and it will seriously increase your computer's operating speed. These disks are now reasonably priced and easily installed with a vendor provided USB cable. You may first be required to reformat it, though. Use only Disk Utility to do this, not any vendor provided maintenance app. They almost always cause problems. I use and recommend LaCie disks, but there are many other good ones available. Finally, get a separate disk which can be dedicated to Time Machine backups.