On: CHIP $9 Computer

[squeaky-clean]

I don't know if this specific one is a good buy, it's just the first thing that came up when I searched "HP Proliant", but here's an example [0]. Search for the names of servers from the past few years on eBay, and you can find some powerful hardware for cheap. Keep in mind they're typically very loud.

[0] http://www.ebay.com/itm/HP-Proliant-DL380-G6-8-Core-Server-1...

[striking → squeaky-clean]

Furthermore, get a motherboard with a common socket maybe a generation or two behind. Some larger companies have been decommissioning old hardware, so you can get CPUs for a magnitude or two less money than before.

[ajford → striking]

Thanks for that! I've been looking at picking up some old PowerEdge units, and never thought of that!