Server generations explained

Used-server listings are full of cryptic generation names, R730 vs R740, DL380 Gen9 vs Gen10. The generation is the single best shortcut to a server's era, CPU family, and RAM type, which together set both its price and what it can do. Here's the map, with the cheap-but-capable homelab sweet spots called out.

Rule of thumb: each step up in generation buys newer/faster CPUs and RAM at a real price premium. For most homelabs, one or two generations back is the value sweet spot.