i believe resources are not an issue anymore, these are socket 775 rigs with quadcore cpu's, the motherboards and cpu's can be traced back to around ~year 2007 models.
Exactly. My rig is S775 motherboard with 4Gb DDR3 (ASUS P5G41T-M LX3) + Celeron e3300 (so-called «computer from trashcan», donated by friend of mine). 3xRX480 with molex-powered raisers, Aerocool KCAS 700W. Rock stable, 600H/s.