PC Power & Cooling Silencer Mk II 650 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 were connected to the power supply single +12 V rail (the EPS12V connector was installed on the +12VB input).
| 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) | 23.75 A (285 W) |
| +12VB | 5 A (60 W) | 10 A (120 W) | 14 A (168 W) | 20 A (240 W) | 23.75 A (285 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 | 140.5 W | 268.6 W | 391.8 W | 536.8 W | 648.4 W |
| % Max Load | 21.6% | 41.3% | 60.3% | 82.6% | 99.8% |
| Room Temp. | 45.2° C | 44.1° C | 45.1° C | 45.5° C | 48.8° C |
| PSU Temp. | 44.9° C | 45.2° C | 45.6° C | 48.0° C | 49.0° C |
| Voltage Stability | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Fail on -12 V | Fail on -12 V | Fail on -12 V | Fail on -12 V |
| AC Power | 164.7 W | 307.5 W | 450.4 W | 627.0 W | 776.0 W |
| Efficiency | 85.3% | 87.3% | 87.0% | 85.6% | 83.6% |
| AC Voltage | 109.5 V | 108.6 V | 106.6 V | 107.0 V | 104.8 V |
| Power Factor | 0.947 | 0.975 | 0.986 | 0.991 | 0.993 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The PC Power & Cooling Silencer Mk II 650 W can really deliver its labeled wattage at high temperatures.
Efficiency was high, between 83.6% and 87.3%. Efficiency at full load was a little bit below what is required by the 80 Plus Silver certification (85%), but as we always explain, tests performed by 80 Plus are done at a room temperature of only 23° C, while this particular power supply we tested at almost 50° C at full load, and efficiency drops with temperature.
Voltages were always inside the allowed range.
Noise and ripple were always at good levels, even though we’d like to see even lower levels at +12 V. At -12 V, however, noise was above the maximum allowed from test two on, peaking 172.8 mV during test five. We’ve also seen high noise levels at this output with the 750 W model from this series. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for +12 V and -12 V, and 50 mV for +5 V and +3.3 V. All values are peak-to-peak figures.
Figure 18: +12VA input from load tester during test five at 648.4 W (81.8 mV)
Figure 19: +12VB input from load tester during test five at 648.4 W (73.3 mV)
Figure 20: +5V rail during test five at 648.4 W (16.6 mV)
Figure 21: +3.3 V rail during test five at 648.4 W (25.8 mV)
Let’s see if we can pull even more from the PC Power & Cooling Silencer Mk II 650 W.