Logisys PS600A12 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.
Since with very low-end power supplies we can’t tell beforehand whether they will be able to deliver their labeled wattage or not, we test them using a different methodology. We increase load little by little, until we find out the maximum the power supply is capable of delivering. As usual, we pull more current/power from the +12 V outputs, as this better reflects the usage of a modern PC, since the CPU and the video cards are connected to these outputs.
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 our tests, the +12VA and +12VB input were connected to the power supply single +12 V rail (the ATX12V connector was installed on the +12VB input of our load tester).
| Input | Test 1 | Test 2 | Test 3 | Test 4 |
| +12VA | 3 A (36 W) | 3.5 A (42 W) | 4.5 A (54 W) | 5.5 A (66 W) |
| +12VB | 2.5 A (30 W) | 3.25 A (39 W) | 4 A (48 W) | 5 A (60 W) |
| +5V | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 A) | 1.5 A (7.5 A) |
| +3.3 V | 1 A (5 W) | 1 A (5 W) | 1.5 A (4.95 W) | 1.5 A (4.95 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 85.6 W | 100.4 W | 125.9 W | 149.4 W |
| % Max Load | 14.3% | 16.7% | 21.0% | 24.9% |
| Room Temp. | 40.7° C | 40.3° C | 39.9° C | 39.7° C |
| PSU Temp. | 41.7° C | 43.3° C | 44.1° C | 44.5° C |
| Voltage Regulation | Fail on +5 V | Fail on +5 V | Fail on +5 V | Fail on +5 V |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 112.8 W | 130.7 W | 161.4 W | 190.4 W |
| Efficiency | 75.9% | 76.8% | 78.0% | 78.5% |
| AC Voltage | 120.5 V | 119.9 V | 118.3 V | 118.4 V |
| Power Factor | 0.608 | 0.618 | 0.636 | 0.648 |
| Final Result | Fail | Fail | Fail | Fail |
| Input | Test 5 | Test 6 | Test 7 | Test 8 |
| +12VA | 6.25 A (75 W) | 7.5 A (90 W) | 8.25 A (99 W) | 9.25 A (111 W) |
| +12VB | 6 A (72 W) | 7 A (84 W) | 8 A (96 W) | 9 A (108 W) |
| +5V | 2 A (10 W) | 2 A (10 W) | 2.5 A (12.5 W) | 2.5 A (12.5 W) |
| +3.3 V | 2 A (6.6 W) | 2 A (6.6 W) | 2.5 A (8.25 W) | 2.5 A (8.25 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 174.5 W | 200.6 W | 225.4 W | 248.4 W |
| % Max Load | 29.1% | 33.4% | 37.6% | 41.4% |
| Room Temp. | 39.7° C | 40.0° C | 40.7° C | 41.7° C |
| PSU Temp. | 44.8° C | 45.3° C | 46.0° C | 47.0° C |
| Voltage Regulation | Fail on +5 V | Fail on +5 V | Fail on +5 V | Fail on +5 V |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 222.6 W | 256.2 W | 290.3 W | 321.2 W |
| Efficiency | 78.4% | 78.3% | 77.6% | 77.3% |
| AC Voltage | 118.1 V | 118.5 V | 118.1 V | 117.7 V |
| Power Factor | 0.660 | 0.670 | 0.679 | 0.686 |
| Final Result | Fail | Fail | Fail | Fail |
| Input | Test 9 | Test 10 | Test 11 | Test 12 |
| +12VA | 10 A (120 W) | 11 A (132 W) | 12 A (144 W) | 13 A (156 W) |
| +12VB | 10 A (120 W) | 11 A (132 W) | 11.75 A (141 W) | 12.75 A (153 W) |
| +5V | 3 A (15 W) | 3 A (15 W) | 3.5 A (17.5 W) | 3.5 A (17.5 W) |
| +3.3 V | 3 A (9.9 W) | 3 A (9.9 W) | 3.5 A (11.55 W) | 3.5 A (11.55 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 272.3 W | 295.3 W | 319.9 W | 341.1 W |
| % Max Load | 45.4% | 49.2% | 53.3% | 56.9% |
| Room Temp. | 42.9° C | 43.2° C | 41.9° C | 43.6° C |
| PSU Temp. | 48.3° C | 44.4° C | 42.5° C | 44.2° C |
| Voltage Regulation | Fail on +5 V | Fail on +5 V | Fail on +5 V | Fail on +5 V |
| Ripple and Noise | Pass | Pass | Pass | Pass |
| AC Power | 358.2 W | 392.4 W | 432.8 W | 475.0 W |
| Efficiency | 76.0% | 75.3% | 73.9% | 71.8% |
| AC Voltage | 117.2 V | 117.1 V | 117.3 V | 116.9 V |
| Power Factor | 0.693 | 0.699 | 0.706 | 0.716 |
| Final Result | Fail | Fail | Fail | Fail |
As expected, the Logisys PS600A12 can’t deliver its labeled wattage: it burned when we tried to pull around 375 W from it. It can only deliver up to 350 W without burning. The component that burned was the +12 rectifier.
Efficiency was always below 80%, between 72% and 78%.
The +5 V output presented voltages above the maximum allowed all the time: the maximum allowed is +5.25 V but this output was always between +5.26 V and +5.38 V. The +12 V and +3.3 V outputs, on the other hand, presented voltages within 3% of their nominal values. The ATX12V specification allows voltages to be up to 5% from their nominal values (10% for the -12 V output).
Noise and ripple levels were always below the maximum allowed. During the test 12, the noise level on the +12VA input was 72.8 mV, on the +12VB input was 72.4 mV, on the +5 V input was 16.6 mV and on the +3.3 V input was 22.4 mV. The maximum allowed is 120 mV for the +12 V and -12 V outputs, and 50 mV for the +5 V, +3.3 V, and +5VSB outputs. All values are peak-to-peak figures.