Slow Late 2013 Imac

[C. Alan]

My father has a late 2013 21.5" Imac with the i5 processor, and 8gb of memory. He recently installed Catalina on it, and since that time it has been dog slow. Like 10 to 15 minute boot times, and time machine only being able to do one backup a day. I at first thought there was a problem with his load of Catalina, so yesterday wiped the HD and reloaded catalina. It did help some, but it is still slow.

On a hunch I downloaded and installed the black magic hard drive speed test and ran it on the main internal hard drive. The read/write speeds were around 80 to 90 mb/s. Are these typical speeds for an older Imac? I'm trying to determine if the hard drive is failing.

 

[r6mile]

Modern versions of OSX, but especially Catalina, run absolutely horrible on an old HDD. Get an external USB3 SSD and use that as the boot drive.

 

[Fishrrman]

One more vote for an external USB3 SSD.
It will transform the performance of the iMac.
You won't believe it until you try it.

I'd suggest buying a 2.5" SATA SSD.
500gb ought to do, 1tb if you need it.

Put it into an enclosure like this:

SABRENT 2.5 Inch SATA to USB 3.0 Tool Free External Hard Drive Enclosure [Optimized for SSD, Support UASP SATA III] Black (EC-UASP)

SABRENT 2.5 Inch SATA to USB 3.0 Tool Free External Hard Drive Enclosure [Optimized for SSD, Support UASP SATA III] Black (EC-UASP)

tinyurl.com

(it just snaps together, no tools needed)

Use disk utility to erase it to APFS, GUID partition format.

Then download CarbonCopyCloner from here:
Carbon Copy Cloner - Download
CCC is FREE to download and use for 30 days.

Use CCC to "clone" the contents of the internal drive to the external SSD.
Then set the SSD to be the boot drive in the startup disk pref pane.

This may "sound like work", but all it takes is a little time, it's a simple process.

Again, you will LIKE the performance increase!