Whether or not you go spelunking inside your iMac may depend on how fast you want the computer to run. OWC sells an NVMe.2 card that replaces the tiny SSD in the 2017 iMac with a 1 or 2 TB INTERNAL SSD which is DRAMATICALLY faster than the Fusion Drive. You can install all the stuff from your external drive, including the OS itself, on that internal SSD and turn the internal rotating platter drive into your Time Machine backups repository. OWC also has free videos (as does iFixIt) that show all the steps involved. You’re still stuck on an older operating system, but you have all the ports on the back of the iMac and you can connect a Thunderbolt Dock from OWC if you need more.

I’m far less adventuresome inside my Macs than I once was. I had original 128 K RAM, then 512 K RAM “fat” Macs, then a Mac Plus in which one could increase the RAM by desoldering a resistor on the motherboard.

Once the Mac evolved to Intel Processors, I experimented on my Mac Pro and managed to Install a “Bare Metal” version of Windows Small Business Server 2008 OS on it to make sure I could run a Windows Outlook and document host for our business (my only experiences with Windows until Boot Camp and then virtualization software that permitted one to run BOTH the macOS and Window came along).

I’m waiting to hear from the Luna Display folks whether I can use the iMac’s ports, keyboard, and mouse with Luna Display. If not, I won’t go down that road.

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Jim Robertson