Power 11 Power Requirements
IBM Power 11 power requirements by machine type: rated voltage, maximum watts, thermal output in BTU per hour, weight and rack units for the S1112, S1122, S1124, L1122, L1124, E1150 and E1180, plus IBM's own measured draw figures.
Power 11 is the first generation in years where the entry machine changes the facilities conversation rather than continuing it. The S1112 is rated at 550 W and will run on a 120 V circuit. At the other end, an E1180 node is rated at 4,850 W and a full system holds four of them. This page gives IBM's published rating and IBM's own measured draw for every Power 11 machine type, so the plan starts from the machine you are actually buying.
Power 11 power requirements by machine type
IBM published electrical and physical ratings, Power 11 family
| Machine type | Model | Operating voltage | Max power | Max thermal | Weight | EIA |
|---|---|---|---|---|---|---|
| 9242-21B | S1112 rack | 100 - 127 or 200 - 240 V ac | 550 W | 1,877 BTU/hr | 20.4 kg | 2U half-wide |
| 9242-21T | S1112 tower | 100 - 127 or 200 - 240 V ac | 550 W | 1,877 BTU/hr | 24.5 kg | Tower |
| 9824-22A | S1122 | 200 - 240 V ac | 2,600 W | 8,871 BTU/hr | 32.2 kg | 2U |
| 9856-22H | L1122 | 200 - 240 V ac | 2,600 W | 8,871 BTU/hr | 32.2 kg | 2U |
| 9824-42A | S1124 | 200 - 240 V ac | 2,950 W | 10,065 BTU/hr | 43.5 kg | 4U |
| 9856-42H | L1124 | 200 - 240 V ac | 2,950 W | 10,065 BTU/hr | 43.5 kg | 4U |
| 9043-MRU | E1150 | 200 - 240 V ac | 5,400 W | 18,245 BTU/hr | 69 kg | 4U |
| 9080-HEU | E1180 | 200 - 208 / 220 - 240 V ac | 4,850 W per node | 16,548 BTU/hr per node | 81.6 kg per node | 5U per node |
All models are single phase at 50 or 60 Hz plus or minus 3 Hz. The E1180 line is per system node: a four-node E1180 is four times these figures plus a 2U system control unit weighing 22.7 kg, giving a 22U system rated near 19.4 kW for the nodes alone. Add 6.8 kg per node for rack hardware.
The S1112 is the number to notice. At 550 W rated and 1,877 BTU/hr it draws less than a Power 9 S922 does at idle, runs on a standard 120 V circuit, and comes in a tower form for a site with no rack at all. For a small IBM i shop still running an S914, this removes the electrical work from the upgrade entirely.
What a Power 11 actually draws
IBM files measured power figures for these machine types in its EU ecodesign technical documentation, testing a high-end and a low-end configuration of each. Every Power 11 filing is recent, which makes this generation the best-documented of the family for anyone sizing a UPS or a cooling budget against real load rather than nameplate.
IBM measured idle and maximum power, Power 11 machine types
| Machine type | Model | Sockets | Measured idle | Measured maximum | Rated maximum |
|---|---|---|---|---|---|
| 9242-21B / 21T | S1112 | 1 | 216.1 ... 240.1 W | 324.5 ... 449.4 W | 550 W |
| 9824-22A / 9856-22H | S1122 / L1122 | 1 | 319.2 ... 499.5 W | 431.2 ... 999.2 W | 2,600 W |
| 9824-22A / 9856-22H | S1122 / L1122 | 2 | 476.7 ... 860.1 W | 708.6 ... 1,772.5 W | 2,600 W |
| 9824-42A / 9856-42H | S1124 / L1124 | 1 | 602.3 ... 683.5 W | 1,288.8 ... 1,603.4 W | 2,950 W |
| 9824-42A / 9856-42H | S1124 / L1124 | 2 | 820.6 ... 1,018.3 W | 1,807.2 ... 2,501.5 W | 2,950 W |
| 9043-MRU | E1150 | 2 | 855.2 ... 1,145.6 W | 1,784.7 ... 2,332.8 W | 5,400 W |
| 9043-MRU | E1150 | 3 | 1,228.6 ... 1,671.1 W | 2,606.2 ... 3,617.9 W | 5,400 W |
| 9043-MRU | E1150 | 4 | 1,888.3 ... 2,180.5 W | 3,371.3 ... 4,643.0 W | 5,400 W |
Each range runs from IBM's tested low-end configuration to its tested high-end configuration. Source: IBM Technical Documentation for EU Regulation 2019/424, filed per machine type. All Power 11 entries are declared operating condition class A3.
The S1112 is the only Power 11 where the rating and the measurement are close: 550 W rated against 449.4 W measured at the high end. Everywhere else the gap is wide. A two-socket S1124 is rated at 2,950 W and measured at 2,501.5 W flat out in IBM's heaviest tested configuration, and a two-socket E1150 is rated at 5,400 W and measured at 2,332.8 W. Size the circuit to the rating, but do not buy UPS capacity or cooling against it without checking the measurement first.
How Power 11 compares against the machine it replaces
Rated maximum power by equivalent model across three generations
| Class | Power 9 | Power 10 | Power 11 |
|---|---|---|---|
| Entry | S914, 1,600 W | S1014, 1,075 W | S1112, 550 W |
| 2-socket 2U | S922, 1,880 W | S1022, 2,240 W | S1122, 2,600 W |
| 2-socket 4U | S924, 2,750 W | S1024, 2,750 W | S1124, 2,950 W |
| Midrange 4-socket | E950, 4,220 W | E1050, 4,950 W | E1150, 5,400 W |
| Enterprise node | E980, 4,130 W | E1080, 4,500 W | E1180, 4,850 W |
Ratings rise modestly at the top of the range and fall sharply at the bottom. The entry class is where the generational change actually shows up in a facilities plan: an S1112 is roughly a third of the rated load of the S914 it replaces. In the mid and upper range the rating creeps up while the work done inside that envelope rises much faster, so the meaningful comparison there is capacity per watt rather than watts alone.
Sizing the circuit from these numbers
Rating drives the circuit
An S1124 at its 2,950 W rating on a 208 V single-phase feed draws about 14.2 A. At the standard 80 percent continuous-load derating that is a 20 A circuit per feed, and a redundant supply pair wants two of them from separate sources.
Measurement drives the UPS
Runtime is calculated against real load, not the rating. A two-socket S1124 measured at 2,501.5 W in IBM's heaviest tested configuration, and far less in a typical one, so a UPS sized to 2,950 W is usually buying runtime that was already there.
Cooling follows BTU
One ton of cooling removes roughly 12,000 BTU/hr. An E1150 at 18,245 BTU/hr is over a ton and a half by itself. Four S1124s in a rack is 40,260 BTU/hr, which is three and a half tons before storage, network or the HMC.
The S1112 changes the question
At 550 W on a 120 V circuit, an S1112 fits where a workstation fits. There is no three-phase conversation, no dedicated 208 V drop, and in the tower form no rack. For a single-partition IBM i shop this is the whole facilities plan.
Sources: IBM's Power 11 scale-out server specifications, the E1180 specifications and the E1150 specifications for ratings, and IBM's EU Regulation 2019/424 technical documentation for measured figures.
Confirm the machine type you are planning around on the Power 11 models page, and check the processor feature on the Power 11 CPU reference, because processor feature and memory count place a machine inside the measured range above. If you are planning a move rather than a new install, IBM i to Power 11 migration and the Power 11 quote checklist cover what to confirm in writing. For the cross-generation facilities walkthrough see AS400System.com's Power server power requirements guide.