Spire BlackDragon 400 W Power Supply Review
Ripple and Noise Tests
Contents
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 Spire BlackDragon 400 W presented noise and ripple levels above the maximum allowed at +3.3 V and +5VSB when delivering 400 W. From our experience, the high jump in noise and ripple from our test four to test five indicates that the unit had surpassed its operating limits. This is not surprising given Spire’s reputation for buying power supplies from Seventeam and labeling them at wattages higher than Seventeam’s intended wattage.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 13.2 mV | 11.2 mV | 10.4 mV | 15.4 mV | 23.8 mV |
| +12VB | 19.6 mV | 11.4 mV | 18.4 mV | 24.8 mV | 33.2 mV |
| +5 V | 10.8 mV | 8.4 mV | 9.8 mV | 12.2 mV | 14.2 mV |
| +3.3 V | 15.0 mV | 9.8 mV | 13.4 mV | 20.2 mV | 54.6 mV |
| +5VSB | 15.2 mV | 11.0 mV | 16.4 mV | 30.2 mV | 119.6 mV |
| -12 V | 19.4 mV | 13.2 mV | 21.6 mV | 26.8 mV | 30.2 mV |
Below you can see the waveforms of the outputs during test five.
Figure 20: +12VA input from load tester during test five at 401.4 W (23.8 mV)
Figure 21: +12VB input from load tester during test five at 401.4 W (33.2 mV)
Figure 22: +5V rail during test five at 401.4 W (14.2 mV)
Figure 23: +3.3 V rail during test five at 401.4 W (54.6 mV)
Let’s see if we can pull more than 400 W from this unit.