My wife bought a 2015 iMac a while back with the intention of using it for photo editing. We later found out that it was one of those models with a soldered 8GB of RAM, which is so fun to use with the shiniest edition of MacOS. It took me 3 flavors of Linux to find one that worked swimmingly:
Devuan: It’s my daily driver on a Lenovo Thinkpad T470s, and it was on my purple keychain drive. Held
Altduring power-on to select the drive as a boot device, and ran through the installer prompts with no issue. On reboot, though, I was faced with a GRUB prompt. Tried every option I could find, but nothing worked to actually boot the new OS.
Elementary OS: Billed as a replacement for Windows and MacOS (but mostly MacOS), it seemed like an interesting option. It’s Ubuntu-based, so could keep my trusty APT around, and is blazing fast compared to an actual Apple OS on this hardware. Unfortunately, the machine decided to take a nap and reboot every hour or so, which is real’ annoying for people who sleep. I was not able to figure out how to play audio with this distro either.
Manjaro: I’d used it a little at my makerspace, and it just works. Chose the XFCE edition. The only real issue is that the built-in speaker volume cannot be adjusted in PulseAudio volume control or any other tool I could think of. Adjustment of volume on a Bluetooth speaker works perfectly. Arch utilities will take some fiddling after years of running Debian, but I’m excited for the challenge.