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 the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each loa
d.
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. In 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 +12V1 rail, while the +12VB input was connected to the power supply +12V2 rail (EPS12V connector).
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 4 A (48 W) | 8 A (96 W) | 12 A (144 W) | 16 A (192 W) | 22.5 A (270 W) |
| +12VB | 4 A (48 W) | 8 A (96 W) | 12 A (144 W) | 16 A (192 W) | 22 A (264 W) |
| +5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 5 A (25 W) | 6 A (30 W) |
| +3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 5 A (16.5 W) | 6 A (19.8 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2.5 A (12.5 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 | 113.5 W | 215.7 W | 328.2 W | 430.2 W | 551.2 W |
| % Max Load | 20.6% | 39.2% | 59.7% | 78.2% | 100.2% |
| Room Temp. | 45.1° C | 44.1° C | 44.7° C | 47.3° C | 46.7° C |
| PSU Temp. | 43.8° C | 44.1° C | 45.0° C | 46.7° C | 49.8° C |
| Voltage Regulation | Failed in -12 V | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 134.9 W | 252.9 W | 389.3 W | 521.1 W | 694.0 W |
| Efficiency | 84.1% | 85.3% | 84.3% | 82.6% | 79.4% |
| AC Voltage | 112.4 V | 110.9 V | 110.1 V | 108.5 V | 106.6 V |
| Power Factor | 0.986 | 0.968 | 0.981 | 0.987 | 0.991 |
| Final Result | Fail | Pass | Pass | Pass | Pass |
The Aerocool E85M-550 can really deliver its labeled wattage at high temperatures.
Since it is based on the same design as the V12XT-600, it presented the exact same performance – and flaws.
Efficiency was high (85.3% peak) when we pulled from 20% to 80% (i.e., from 110 W to 440 W) from its labeled maximum power. At full load load (550 W), however, efficiency dropped to 79.4%. As we always point out, Ecos Consulting, the company behind the 80 Plus certification, tests power supplies at 23° C, and we test power supplies at 45° or higher, and efficiency drops with temperature. So we believe our results to be more realistic.
Voltage regulation was faulty during test one, with the -12 V output above the maximum allowed, at -10.66 V (the maximum allowed is -10.80 V, or 10%). During all other tests, voltages were inside specifications.
Noise and ripple, though always inside specs, were very high during test five, with the +12 V outputs almost touching the 120 mV limit. The X12XT-600 also presented a high noise level at +3.3 V output, which wasn’t observed on the E85M-550. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for +12 V and -12 V and 50 mV for +5 V and +3.3 V. All values are peak-to-peak figures.
Figure 18: +12VA input from load tester during test five at 551.2 W (117.2 mV)
Figure 19: +12VB input from load tester during test five at 551.2 W (107.4 mV)
Figure 20: +5V rail during test five at 551.2 W (21.2 mV)
Figure 21: +3.3 V rail during test five at 551.2 W (28.6 mV)
Let’s see if we can pull even more from the Aerocool E85M-550.
