PC Power & Cooling Silencer Mk III 750 W Power Supply Review
Voltage Regulation Tests
Contents
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. We consider a power supply as “flawless” if it shows voltages within 3% of their nominal values. In the table below, you can see the power supply voltages during our tests and, in the following table, the deviation, in percentage, of their nominal values.
The PC Power & Cooling Silencer Mk III 750 W presented voltages within the allowed margin.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | +12.12 V | +12.06 V | +11.98 V | +11.92 V | +11.86 V |
| +12VB | +12.10 V | +12.02 V | +11.90 V | +11.80 V | +11.72 V |
| +5 V | +5.10 V | +5.05 V | +4.99 V | +4.92 V | +4.84 V |
| +3.3 V | +3.33 V | +3.27 V | +3.22 V | +3.16 V | +3.15 V |
| +5VSB | +5.03 V | +4.96 V | +4.89 V | +4.82 V | +4.78 V |
| -12 V | -12.00 V | -12.03 V | -12.07 V | -12.11 V | -12.12 V |
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 1.00% | 0.50% | -0.17% | -0.67% | -1.17% |
| +12VB | 0.83% | 0.17% | -0.83% | -1.67% | -2.33% |
| +5 V | 2.00% | 1.00% | -0.20% | -1.60% | -3.20% |
| +3.3 V | 0.91% | -0.91% | -2.42% | -4.24% | -4.55% |
| +5VSB | 0.60% | -0.80% | -2.20% | -3.60% | -4.40% |
| -12 V | 0.00% | -0.25% | -0.58% | -0.91% | -0.99% |
Let’s discuss the ripple and noise levels on the next page.
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page title=”Ripple and Noise Tests”]
Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.
The PC Power & Cooling Silencer Mk III 750 W provided extremely low ripple and noise levels, as you can see in the table below.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 9.6 mV | 15.4 mV | 19.6 mV | 24.8 mV | 30.2 mV |
| +12VB | 13.4 mV | 20.0 mV | 27.2 mV | 33.8 mV | 44.2 mV |
| +5 V | 8.4 mV | 10.2 mV | 10.2 mV | 11.8 mV | 16.4 mV |
| +3.3 V | 6.6 mV | 8.4 mV | 10.4 mV | 13.4 mV | 22.4 mV |
| +5VSB | 4.2 mV | 5.4 mV | 7.2 mV | 8.4 mV | 13.8 mV |
| -12 V | 11.8 mV | 13.2 mV | 15.4 mV | 16.6 mV | 27.2 mV |
Below you can see the waveforms of the outputs during test five.
Figure 23: +12VA input from load tester during test five at 751.4 W (30.2 mV)
Figure 24: +12VB input from load tester during test five at 751.4 W (44.2 mV)
Figure 25: +5V rail during test five at 751.4 W (16.4 mV)
Figure 26: +3.3 V rail during test five at 751.4 W (22.4 mV)
Let’s see if we can pull more than 750 W from this unit.