To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the ERV650SWT's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).
Ripple suppression is pretty good at +12V and 5VSB, decent enough at 5V, and satisfactory at 3.3V. Remember that this is an SFX unit with limited space on its mainboard, so the number of filtering caps is kept low. Really, you can't fairly compare such a compact platform to larger ATX PSUs.
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 0.01 V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.
Ripple At Full Load
Ripple At 110-Percent Load
Ripple At Cross-Load 1
Ripple At Cross-Load 2
MORE: Best Power Supplies
MORE: All Power Supply Content