Aerocool HorsePower 750 W Power Supply Review
Load Tests
Contents
We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.
First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching how the reviewed unit behaved under each load. In the table below we list the load patterns we used and the results for each load.
If you add all the power listed for each test, you may find a different value than what is posted under “Total” below. Since each output can vary slightly (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. On the “Total” row we are using the real amount of power being delivered, as measured by our load tester.
The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test the +12VA input was connected to the power supply +12V3 and +12V4 rails, while the +12VB input was connected to the power supply +12V1 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 5 A (60 W) | 11 A (132 W) | 16 A (192 W) | 22 A (264 W) | 27 A (324 W) |
| +12VB | 5 A (60 W) | 10 A (120 W) | 16 A (192 W) | 21 A (252 W) | 27 A (324 W) |
| +5V | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) | 10 A (50 W) |
| +3.3 V | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) | 10 A (33 W) |
| +5VSB | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2.5 A (12.5 W) | 3 A (15 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 148.4 W | 297.2 W | 445.4 W | 592.9 W | 751.2 W |
| % Max Load | 19.8% | 39.6% | 59.4% | 79.1% | 100.2% |
| Room Temp. | 45.7° C | 46.0° C | 47.8° C | 46.9° C | 49.8° C |
| PSU Temp. | 44.0° C | 44.8° C | 46.2° C | 48.9° C | 52.7° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 184.1 W | 354.7 W | 532.5 W | 720.0 W | 941.0 W |
| Efficiency | 80.6% | 83.8% | 83.6% | 82.3% | 79.8% |
| AC Voltage | 112.5 V | 110.6 V | 108.4 V | 106.2 V | 103.5 V |
| Power Factor | 0.998 | 0.996 | 0.997 | 0.998 | 0.998 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
Aerocool HorsePower 750 W can really deliver its labeled power at high temperatures.
Efficiency was between 79.8% and 83.8%.
Voltage regulation was exceptional, with all voltages within 3% from their nominal values (the only exception was the -12 V output during test five) – i.e., values closer to their “face value” than required, as the ATX12V specification allows voltages to be within 5% from their nominal values (10% for -12 V).
Noise and ripple was below the maximum allowed, which is great. With other power supplies that we reviewed that are based on this same project we achieved higher noise levels during test five, almost touching the 120 mV limit, which didn’t happen with this unit. This result can be easily explained by the fact that we recently changed the load pattern used in our power supply reviews in order to provide a smoother transition between load patterns and a better balance between the +12VA and +12VB inputs of our load tester. Translation: in our older reviews we pulled more from the +12 V outputs during test five than on this review. The noise level, however, was still at a value that we consider high – we like to see noise levels at half of the maximum allowed or less.
Below you can see the results for test five. The maximum allowed is 120 mV on +12 V and 50 mV on +5 V and +3.3 V. All these numbers are peak-to-peak figures.
Figure 16: +12VA input from load tester at 751.2 W (77.4 mV).
Figure 17: +12VB input from load tester at 751.2 W (84.5 mV).
Figure 18: +5 V rail with power supply delivering 751.2 W (11.8 mV).
Figure 19: +3.3 V rail with power supply delivering 751.2 W (16.6 mV).
Now let’s see if this unit can deliver more than 750 W.