Ripple Measurements
Ripple Measurements
To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the Edison M 750's rails. The limits are, according to the ATX specifications, 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).
Test | 12V (mV) | 5V (mV) | 3.3V (mV) | 5VSB (mV) | Pass/Fail |
---|---|---|---|---|---|
10% Load | 6.4 | 5 | 6.3 | 5.4 | Pass |
20% Load | 8.8 | 4.2 | 6.4 | 6.6 | Pass |
30% Load | 10.8 | 5 | 6.7 | 7.6 | Pass |
40% Load | 13.2 | 5 | 9.6 | 8.2 | Pass |
50% Load | 15 | 5.6 | 10 | 9.4 | Pass |
60% Load | 19.1 | 5.5 | 12.3 | 10.2 | Pass |
70% Load | 22.5 | 11.8 | 12.7 | 11.8 | Pass |
80% Load | 25.7 | 35.8 | 14.2 | 12.4 | Pass |
90% Load | 29.9 | 34.9 | 17 | 13.9 | Pass |
100% Load | 34.6 | 37.6 | 19.1 | 15.2 | Pass |
110% Load | 40.1 | 40.7 | 19.3 | 16.2 | Pass |
Crossload 1 | 7.7 | 5.4 | 7.4 | 11.1 | Pass |
Crossload 2 | 33.1 | 34 | 14.2 | 14 | Pass |
Ripple suppression on all rails (except for 5V) is very good overall. On the 5V rail, we noticed a sudden increase in ripple with 80-percent load and up. Incidentally, this was also the case with the Edison M 650W that we tested previously. We would advise Seasonic to look at the DC-DC converter that generates the 5V rail to find the source of this sudden increase at higher loads. It might not be a serious problem that could affect your system’s stability, since ripple on this rail is still lower than the ATX limit. But it's still a shame to see performance loss over this matter.
Ripple Oscilloscope Screenshots
The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.