Amacrox Free Earth 85PLUS 650 W Power Supply Review
Load Tests (Sample 1)
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 o
f 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 and during all tests 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 | 5 A (60 W) | 10 A (120 W) | 15 A (180 W) | 20 A (240 W) | 26 A (312 W) |
| +12VB | 5 A (60 W) | 10 A (120 W) | 14 A (168 W) | 20 A (240 W) | 23 A (276 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 | 137.4 W | 262.8 W | 386.7 W | 531.7 W | 654.0 W |
| % Max Load | 21.1% | 40.4% | 59.5% | 81.8% | 100.6% |
| Room Temp. | 41.3° C | 41.9° C | 43.5° C | 43.9° C | 30.3° C |
| PSU Temp. | 46.1° C | 46.6° C | 46.6° C | 49.2° C | 32.4° C |
| Voltage Stability | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 162.0 W | 305.5 W | 452.5 W | 634.0 W | 797.0 W |
| Efficiency | 84.8% | 86.0% | 85.5% | 83.9% | 82.1% |
| AC Voltage | 115.8 V | 114.7 V | 112.8 V | 109.3 V | 105.6 V |
| Power Factor | 0.971 | 0.986 | 0.992 | 0.996 | 0.996 |
| Final Result | Pass | Pass | Pass | Pass | Fail |
For some reason the reviewed unit couldn’t deliver its labeled power at high temperatures. When the unit was hot with us pulling 650 W from it, it shut down. At a room temperature of only 30° C, it would deliver 650 W for only 45 seconds.
Because of this problem, we requested a second sample from Amacrox, so we could re-test this power supply. The results for this second sample are published on next page.
We also saw over current protection (OCP) kicking in during test five, which is good. Usually with 650 W power supplies we try to pull 24.5 A from +12VA and 24.5 A from +12VB during our 650 W test, but pulling 24 A or more from +12VB (which was connected to the power supply +12V2 rail) the unit wouldn’t turn on, so we had to configure +12VB with 23 A and +12V1 with 26 A.
Voltages were always within their required range and ripple and noise were always low. Below you can see noise and ripple levels during test five.
Figure 16: +12VA input from load tester during test five at 654.0 W (43.2 mV).
Figure 17: +12VB input from load tester during test five at 654.0 W (38.6 mV).
Figure 18: +5V rail during test five at 654.0 W (21.4 mV).
Figure 19: +3.3 V rail during test five at 654.0 W (25.2 mV).