To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the ST60F-TI's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).
The secondary side could use more filtering caps, though that'd result in higher energy losses. This is why ripple suppression on the +12V rail is mediocre. The same goes for the 3.3V rail, where strangely enough ripple peaks during the 80% load test. On the contrary, ripple suppression on the 5V and 5VSB rails is pretty good.
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.