I’m looking at some old Intel and Pentium CPUs that are in a NUC. Are cores and max clock speed the only things that matter? Would a Pentium be good enough to run Immich? I have a i7-4790, and the NUCs I’m looking at range from a Pentium J5005 to a i3-1115G4. I do run Docker, does that affect anything?
Look at benchmarks.
Single or multi-core performance will matter more depending on your workload.