High Power Direct12 BR 850 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, both inputs were connected to the power supply’s single +12 V rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 6 A (72 W) | 13 A (156 W) | 18.5 A (222 W) | 25 A (300 W) | 31 A (372 W) |
| +12VB | 6 A (72 W) | 13 A (156 W) | 18.5 A (222 W) | 25 A (300 W) | 31 A (372 W) |
| +5 V | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) | 12 A (60 W) |
| +3.3 V | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) | 12 A (39.6 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 | 174.6 W | 362.8 W | 512.9 W | 684.9 W | 847.1 W |
| % Max Load | 20.5% | 42.7% | 60.3% | 80.6% | 99.7% |
| Room Temp. | 44.8° C | 44.8° C | 45.0° C | 49.6° C | 45.6° C |
| PSU Temp. | 49.1° C | 49.1° C | 50.6° C | 52.3° C | 56.3° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Failed at +3.3 V |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 208.4 W | 422.1 W | 601.2 W | 813.0 W | 1031.0 W |
| Efficiency | 83.8% | 86.0% | 85.3% | 84.2% | 82.2% |
| AC Voltage | 117.2 V | 114.5 V | 112.8 V | 110.8 V | 106.8 V |
| Power Factor | 0.926 | 0.974 | 0.984 | 0.988 | 0.992 |
| Final Result | Pass | Pass | Pass | Pass | Fail |
The High Power Direct12 BR 850 W can really deliver its labeled wattage at high temperatures.
Efficiency was between 82.2% and 86.0% during our tests. It is great to see that this unit can really present efficiency above 82% at full load under higher temperatures, since several power supplies with the 80 Plus Bronze certification fail to provide 82% minimum efficiency under this scenario. Voltages were closer to their nominal values (3% regulation) during tests one, two, and three, which is great. During test four, the +3.3 V output was outside this tighter range (at +3.17 V), but still inside the allowed margin. During test five, however, the +3.3 V output was below the minimum allowed, at +3.10 V. The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.
Let’s discuss the ripple and noise levels on the next page.