3R System AK 500 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 +12V2 rails, while the +12VB input was connected to the power supply +12V1 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 4 A (48 W) | 7 A (84 W) | 10.5 A (126 W) | 14 A (168 W) | 17.5 A (210 W) |
| +12VB | 4 A (48 W) | 7 A (84 W) | 10.5 A (126 W) | 14 A (168 W) | 17.5 A (210 W) |
| +5 V | 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 | 102.8 W | 195.6 W | 300.4 W | 403.0 W | 503.4 W |
| % Max Load | 20.6% | 39.1% | 60.1% | 80.6% | 100.7% |
| Room Temp. | 46.5° C | 45.3° C | 45.0° C | 45.6° C | 48.6° C |
| PSU Temp. | 49.4° C | 49.4° C | 49.6° C | 51.8° C | 53.8° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 124.7 W | 230.5 W | 355.6 W | 487.3 W | 632.0 W |
| Efficiency | 82.4% | 84.9% | 84.5% | 82.7% | 79.7% |
| AC Voltage | 117.9 V | 116.4 V | 115.1 V | 114.0 V | 111.7 V |
| Power Factor | 0.952 | 0.975 | 0.985 | 0.988 | 0.990 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The 3R System AK 500 can really deliver its labeled wattage at high temperatures.
Efficiency was between 82.7% and 84.9% when we pulled between 20% and 80% of the power supply labeled wattage (i.e., between 100 W and 400 W). These are terrific numbers for an entry-level power supply. At full load, however, efficiency dropped a little bit below the 80% mark, at 79.7 percent. This is very common, as we test power supplies at very high temperatures (between 45° and 50° C), while the 80 Plus certification tests are performed at 23° C, and efficiency drops with the temperature.
Interestingly, this unit officially received the 80 Plus Bronze certification, but the manufacturer decided to sell it as a standard 80 Plus unit. This was a very honest move, as this product can’t provide 82% efficiency at real-world temperatures.
Voltages were closer to their nominal values (3% regulation) during tests three through five, which is great. During test one, the +5 V and +12 V outputs were outside this tighter range (at +5.19 V and +11.61 V, respectively), but still inside the allowed margin. During test two, only the +5 V output was outside this tighter range (at +5.15 V), but again, inside the allowed margin. 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.