Summer Simulator 2014 AKA Primecoin experimental mining farm:

2.0 kW Idle, 3.5+ kW load

Equivalent to ~18x 3.4 GHz Xeon HT processors.
Disks: 18x 15k RPM SCSI drives
Fans: 68 internal + 2 pedestal

Electrical running costs: $25+ per day

Primes per second: Classified.