This is my census mining operation that logs on to realms and gathers data about online players. Everything is fully automated, including logging into realms and creating characters.

Each machine is running between 20 and 40 instances of WOW.

The rack is an old picture, we have 2 racks x 7 machines each, plus a shelf with 5.

Rack machine specs:
AMD 64x2 4400 dual cores, 4GB - 8GB RAM, Geforce 7300 - 8500 cards, Windows XP 64, SATA 8MB buffer drives.