homelab

They are Ultra Small Form Factors PCs from the big brands. Lenovo ThinkCenter Tiny, HP EliteDesk/ProDesk Mini and Dell Optiplex Micro. They are small, quiet, they don't pull a lot of power and they are not too expensive when you get second-hand ones that are decomissioned from business environments.

The only thing is that they don't have a lot of room for expansion/storahe. Some some have 1x M.2 port for NVMe + 1x 2.5" slot, some have 2x M.2 ports. Most don't have PCie ports (apart a few Tinys) but if you want affordable nodes, they can be great!

Edit: you can read more here https://www.servethehome.com/introducing-project-tinyminimicro-home-lab-revolution/