Answer
It depends far more on the machine type than the generation. Within a single generation the spread can be enormous, and the entry machines have been getting smaller while the enterprise machines have grown.
Rated maximum power for the entry model of each generation:
- Power 5, eServer i5 520 (9406-520): 750 W
- Power 6, Power 520 (8203-E4A): 770 W
- Power 7, Power 720 (8202-E4B): 750 W
- Power 8, Power S812 (8284-21A): 1,225 W
- Power 9, Power S914 (9009-41A): 1,600 W
- Power 10, Power S1014 (9105-41B): 1,075 W
- Power 11, Power S1112 (9242-21B): 550 W
Rated maximum power for the 4U scale-out model of each recent generation:
- Power 8, Power S824 (8286-42A): 2,300 W
- Power 9, Power S924 (9009-42A): 2,750 W
- Power 10, Power S1024 (9105-42A): 2,750 W
- Power 11, Power S1124 (9824-42A): 2,950 W
The enterprise machines publish per node rather than per system. A Power 9 E980 node is 4,130 W, a Power 10 E1080 node is 4,500 W and a Power 11 E1180 node is 4,850 W, and a fully populated system holds four of them plus a system control unit.
The oldest machines are the outliers in the other direction. A Power 5 eServer i5 595 (9406-595) is a three-phase 19.4 kW frame, which is as much as four Power 11 E1180 nodes.