Late 2013 iMac (Downgrade High Sierra to Yosemite) Time Machine or SuperDuper! Backup?

northernnights wrote:

Will restoring backups from Superduper or Time Machine make me revert back to High Sierra after I downgrade (because that’s the macOS I cloned/Time Machined)?

Yes, if you clone over everything. But the beauty of a clone is that because it is the identical file system as the source, you can drag and drop just your user folder across to the downgraded disk. It's best to do this folder by folder (i.e. Documents, Downloads, Pictures , Movies, etc.) and drag the contents, not the folder themselves to the corresponding folders. Leave the ~/Library behind as that could be a source if issues when reverting.

I would go with the first solution, using the clone.

When you say then boot from the clone, that means you will be working from High Sierra, I thought you wanted to be working from Yosemite? Or do you want the ability to boot into either so you can use some of the newer applications?

But before you go through all that you probably should troubleshoot your High Sierra install, it's likely something that can be sorted. To do that you can run Etrecheck. 

It is a diagnostic tool that's very useful to us in finding problems. Also it will give us further specs on your Mac. After it runs post the log file here. It will contain no personal information. Allowing full drive access will improve the quality of the report.

To post the log file click on share report and use the Additional Text icon in your reply window.

Overall, the biggest issue with speed would seem to be the very slow 5400 RPM hard drive. Uninstall AppCleaner as per the developer's instructions these third party cleaners are not recommended and can damage your Mac. Backblaze may be using unnecessary resources.

I was wondering about that. Your first report had a rather long runtime for a "Good" rating. Since Etrecheck relies heavily on runtime to report hard drive failure. I'd check that against Drive Dx.

https://binaryfruit.com/drivedx

It's a more robust utility to check the health of a hard drive. It will not repair anything just check. If you need help with the output you can post it here.

Ok, we'll look over the report.

Hello there! I'm sharing this screenshot with everyone having problems with macOS High Sierra. I've always noticed a huge difference in performance from Sierra to High Sierra, and now I'm sure there's something very shady behind that version of macOS. Remember battery gate? ;)