My cheapskate 2015 “relic” came from this recycling firm in Leeds with no OS. It is a Hewlett-Packard EliteDesk 800 G1; Intel Core i7-4790 nominal 3.60 GHz; Intel Xeon E3-1200 Integrated Graphics; 1 TiB SSD; with 4 x 8GB DDR3 RAM.
With nproc = 8 my first builds seem to run nicely on -j 7 (by default nproc -1, fully adjustable, thanks to @SteadfasterX’s [HOWTO] build /e/ the (full) classic way (no docker, no scripts, just 'make').