Interesting possibility! In this case, I don’t think that’s happening since it appears as Unknown in the SATA section of System Information.
Thanks! I figured that these techniques weren’t necessarily things people did every day, so it was worth a few more words to explain how to do them as well.
Fingers crossed it doesn’t come to that, since Apple doesn’t seem to be doing too well with repairing Mac Pros.
Apple has a policy of supporting the two previous macOS versions, so that would be Mojave and High Sierra. Once the next version of macOS comes out, however, High Sierra will be kicked off the back of the train. Another thing to consider when pondering an upgrade.
In thinking about your situation, I would recommend buying a new iMac right away. Doing that gives you the opportunity to transition to it gently while the old iMac continues to work as you’ve come to expect. Also, it will be loads faster for the exact sort of things you’re doing. In fact, I’d buy the new iMac, start using it immediately, and only rely on the old iMac for parts of the workflow that can’t be transitioned immediately. Those can then be moved over as you have time.
DiskWarrior has long been a great app, but I have to say, I haven’t used it in decades. Mac drives, particularly SSDs in my experience, don’t seem to suffer directory problems nearly as often as they used to. If Disk Utility can’t fix something, I’d prefer to reformat and restore rather than trust that any third-party could do better than Apple’s own engineers, particularly given that APFS documentation is still sparse, as I understand it. I would never recommend holding up an upgrade for DiskWarrior. Just make sure you have great backups.
Interestingly, the old 2014 iMac I got back from @jcenters had a Fusion Drive, and it looks like he split it. The SSD is largely non-functional (the Finder asks to initialize it, but it always fails in Disk Utility) and while the hard drive seems to work, I strongly suspect that the machine’s flakiness is due to having the dead SSD in there.