Enermax PRO87+ 500 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 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 load.
If you add all the powers listed for each test, you may find
a different value than what is posted under “Total” below. Since each output can have a slight variation (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 and +12V3 rails, while the +12VB input was connected to the power supply +12V2 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 4 A (48 W) | 7.5 A (90 W) | 11 A (132 W) | 14 A (168 W) | 17.5 A (210 W) |
| +12VB | 3 A (36 W) | 7 A (84 W) | 10.5 A (126 W) | 14 A (168 W) | 17.5 A (210 W) |
| +5V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) |
| +3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 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 | 104.6 W | 204.1 W | 307.6 W | 404.7 W | 502.6 W |
| % Max Load | 20.9% | 40.8% | 61.5% | 80.9% | 100.5% |
| Room Temp. | 45.9° C | 44.6° C | 44.7° C | 46.3° C | 45.0° C |
| PSU Temp. | 50.5° C | 49.5° C | 49.4° C | 51.2° C | 49.3° C |
| Voltage Stability | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 118.4 W | 224.8 W | 344.6 W | 458.2 W | 581.4 W |
| Efficiency | 88.3% | 90.8% | 89.3% | 88.3% | 86.4% |
| AC Voltage | 114.5 V | 114.3 V | 343.8 V | 110.2 V | 110.2 V |
| Power Factor | 0.984 | 0.986 | 0.994 | 0.996 | 0.997 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The Enermax PRO87+ 500 W can really deliver its labeled wattage at high temperatures.
Efficiency was always very high, between 88.3% and 90.8% when we pulled between 20% and 80% of the labeled wattage (i.e., between 100 W and 400 W). At full load (500 W) efficiency dropped to 86.4%, still a very high efficiency. Being an 80 Plus Gold unit, this power supply should deliver 87% efficiency at full load. However, as we always explain, tests performed by 80 Plus are done at a room temperature of only 23° C, while this particular power supply we tested at almost 50° C at full load, and efficiency drops with temperature.
Voltages were always inside the allowed range.
Noise and ripple were always extremely low, except on -12 V output, which peaked 119.8 mV during test five. 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 19: +12VA input from load tester during test five at 502.6 W (26.2 mV)
Figure 20: +12VB input from load tester during test five at 502.6 W (26.2 mV)
Figure 21: +5V rail during test five at 502.6 W (22.2 mV)
Figure 22: +3.3 V rail during test five at 502.6 W (20.8 mV)
Let’s see if we can pull even more from the Enermax PRO87+ 500 W.