proxmox

The Late 2012 Mac Mini Server makes a cheap Proxmox VE node and is the last fully upgradeable Mac Mini. Its two SO-DIMM slots support 16GB of RAM, and its two 2.5-inch SATA bays can hold a boot disk and a datastore. Apple soldered the RAM in 2014 and moved the line to ARM in 2020, so newer Minis either cannot take more memory or cannot run x86 virtualization.

Its quad-core mobile Ivy Bridge i7 keeps power use modest for four cores. The whole machine is a 19cm-square box that fits on a shelf.