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 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 of 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.
+12V1 and +12V2 are the two independent +12V inputs from our load tester and during out tests the +12V1 input was connected to the power supply +12V1 (main motherboard cable and peripheral power connectors), while the +12V2 input was connected to the power supply +12V2 rail (ATX12V connector). Thus on this review+12V1 and +12V2 really represent the power supply rails with the same name.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12V1 | 3.5 A (42 W) | 7 A (84 W) | 10 A (120 W) | 13 A (156 W) | 16 A (192 W) |
| +12V2 | 3 A (36 W) | 6.5 A (78 W) | 10 A (120 W) | 13 A (156 W) | 16 A (192 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) | 0.8 A (9.6 W) |
| Total | 97.9 W | 190. W | 286. W | 375.8 W | 467.1 W |
| % Max Load | 21.3% | 41.3% | 62.2% | 81.7% | 101.5% |
| Room Temp. | 47.8° C | 47.1° C | 47.6° C | 48.7° C | 48.7° C |
| PSU Temp. | 50.7° C | 50.2° C | 49.6° C | 50.7° C | 52.1° C |
| Voltage Stability | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 118 W | 222 W | 338 W | 452 W | 580 W |
| Efficiency | 83.0% | 85.6% | 84.6% | 83.1% | 80.5% |
| Final Result | Pass | Pass | Pass | Pass | Pass |
If you pull up to 80% of this power supply labeled capacity (i.e., up to 368 W) you will have a very good efficiency. At full load efficiency drops, but is still above the 80% mark.
Voltage was always between 3% of their nominal value, which is always good to see, except the -12 V output, which is normal to happen and was still with 5% of its nominal value. ATX specs say that voltages have to be within 5% their nominal values (10% for -12 V).
Ripple and noise level was the highlight from this product. The only problem we saw was that noise level at +12V2 was far higher than at +12V1, but still within specs. See the results below, remembering that the maximum allowed is 50 mV for +5 V and +3.3 V outputs and 120 mV for +12 V outputs. All figures are peak-to-peak values.
Figure 15: Noise level at +12V1 with the reviewed power supply delivering 467.1 W (21.8 mV).
Figure 16: Noise level at +12V2 with the reviewed power supply delivering 467.1 W (61 mV).
Figure 17: Noise level at +5 V with the reviewed power supply delivering 467.1 W (21.2 mV).
Figure 18: Noise level at +3.3 V with the reviewed power supply delivering 467.1 W (22.6 mV).
Now let’s see if we can pull even more power from Zalman ZM460-APS.
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