older-era computers aren't all great on power. the different between something like a c2d and i3 was immense. it's still absolutely fucking mental how little power the apple arm shit draws (for what it does). something like a kill-a-watt or so would be the easiest to do some measurement

I'll hit you up elsewhere a bit later and share some ideas for backup :)

I'm using two 16TB HDDs in a Raid 1 configuration (one mirrors the other) on my Linux Mint daily driver. I just set it up with mdadm. There are obviously much more complicated ways, but this was simple and convenient for my needs right now.

for backups have a look at kopia. not only for the functionality, but for the fact that this whole thing is a static-linked single go binary. drop it where you need it, and you're done.