Amacrox Free Earth 88PLUS 600 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 power listed for each test, you may find a different value than what is posted under &ldqu
o;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’s +12V3 and +12V4 rails, while the +12VB input was connected to the power supply’s +12V2 rail (EPS12V connector).
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 4 A (48 W) | 9 A (108 W) | 13 A (156 W) | 17.5 A (210 W) | 22.5 A (270 W) |
| +12VB | 4 A (48 W) | 9 A (108 W) | 13 A (156 W) | 17.5 A (210 W) | 22 A (264 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) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 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 | 113.3 W | 238.4 W | 350.1 W | 472.2 W | 599.4 W |
| % Max Load | 18.9% | 39.7% | 58.4% | 78.7% | 99.9% |
| Room Temp. | 46.3° C | 45.2° C | 45.3° C | 46.6° C | 45.8° C |
| PSU Temp. | 49.0° C | 49.3° C | 49.9° C | 50.9° C | 52.0° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 128.4 W | 268.5 W | 397.7 W | 543.7 W | 706.0 W |
| Efficiency | 88.2% | 88.8% | 88.0% | 86.8% | 84.9% |
| AC Voltage | 113.3 V | 112.2 V | 111.2 V | 109.6 V | 107.8 V |
| Power Factor | 0.956 | 0.977 | 0.987 | 0.993 | 0.995 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The Amacrox Free Earth 88PLUS 600 W can really deliver its labeled wattage at high temperatures.
We were definitely impressed by the efficiency achieved by this unit: it presented efficiency above 88% (88.8% peak) when we pulled between 20% and 60% from its labeled load (i.e., between 120 W and 360 W). At 80% load (i.e., 480 W) efficiency was still high at almost 87%. And at full load (600 W) efficiency was at 84.9%. 80 Plus Silver certification is given to power supplies capable of achieving efficiency of at least 85% at light (20%) and full (100%) loads and at least 88% at typical (50%) load at a room temperature of 23° C. This unit from Amacrox could really deliver this performance level at higher temperatures (many power supplies can’t sustain their 80 Plus levels at higher temperatures, as efficiency decreases with temperature), and we were particularly impressed by the 88% efficiency at light load.
Voltages were always inside the allowed range.
Noise and ripple levels were always at very low levels. Below you can see the results for the power supply outputs during test number five. The maximums allowed are 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 599.4 W (48.6 mV)
Figure 19: +12VB input from load tester during test five at 599.4 W (36.2 mV)
Figure 20: +5V rail during test five at 599.4 W (19.8 mV)
Figure 21: +3.3 V rail during test five at 599.4 W (27.2 mV)
Let’s see if we can pull even more from the Amacrox Free Earth 88PLUS 600 W.