Seasonic X-Series KM3 650 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 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.
The Seasonic X-Series KM3 650 W presented outstanding voltage regulation, with all its main positive voltages within 1% of their nominal values. (Seasonic promises 2% voltage regulation for this power supply.)
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | +12.06 V | +12.04 V | +12.02 V | +12.00 V | +11.98 V |
| +12VB | +12.06 V | +12.03 V | +12.00 V | +11.97 V | +11.94 V |
| +5 V | +5.03 V | +5.02 V | +5.02 V | +5.01 V | +5.01 V |
| +3.3 V | +3.33 V | +3.31 V | +3.31 V | +3.31 V | +3.30 V |
| +5VSB | +5.08 V | +5.05 V | +5.02 V | +4.99 V | +4.96 V |
| -12 V | -11.41 V | -11.54 V | -11.66 V | -11.84 V | -12.01 V |
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 0.50% | 0.33% | 0.17% | 0.00% | -0.17% |
| +12VB | 0.50% | 0.25% | 0.00% | -0.25% | -0.50% |
| +5 V | 0.60% | 0.40% | 0.40% | 0.20% | 0.20% |
| +3.3 V | 0.91% | 0.30% | 0.30% | 0.30% | 0.00% |
| +5VSB | 1.60% | 1.00% | 0.40% | -0.20% | -0.80% |
| -12 V | 5.17% | 3.99% | 2.92% | 1.35% | -0.08% |
Let’s discuss the ripple and noise levels on the next page.