Seasonic G-550 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 its 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.
As you can see, the positive voltages of the Seasonic G-550 were always within 3% of their nominal values.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | +12.28 V | +12.26 V | +12.20 V | +12.20 V | +12.16 V |
| +12VB | +12.28 V | +12.25 V | +12.20 V | +12.18 V | +12.15 V |
| +5 V | +5.05 V | +5.05 V | +5.01 V | +5.01 V | +5.00 V |
| +3.3 V | +3.36 V | +3.34 V | +3.28 V | +3.30 V | +3.29 V |
| +5VSB | +4.98 V | +4.97 V | +4.92 V | +4.90 V | +4.86 V |
| -12 V | -12.28 V | -12.26 V | -12.20 V | -12.20 V | -12.16 V |
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 2.33% | 2.17% | 1.67% | 1.67% | 1.33% |
| +12VB | 2.33% | 2.08% | 1.67% | 1.50% | 1.25% |
| +5 V | 1.00% | 1.00% | 0.20% | 0.20% | 0.00% |
| +3.3 V | 1.82% | 1.21% | -0.61% | 0.00% | -0.30% |
| +5VSB | -0.40% | -0.60% | -1.60% | -2.00% | -2.80% |
| -12 V | -5.33% | -3.92% | -1.33% | 0.00% | 2.08% |
Let’s discuss the ripple and noise levels on the next page.