Already read the manual this morning
Most models are of a 2+1 1200w configuration, or 2400w with a spare. Also looks like a 3 x 1000w configuration (no spare) is available for a completely maxed out system.
Remember, the top system was made to handle 8 AMD FireStream 9370's. They'd use up about 1800w (load) by themselves.
-Oops. Make that, they they are not different power supply units. It's 1200w @220 and 100w @ 110. I had an old Compaq server like that- 750w per unit at 220v, only 500w at 110v.