To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on SX500-LG's rails. The limits are, according to the ATX specification, 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).
Ripple suppression on the +12V rail wasn't top-notch, but it was decent for a unit of this size (although we believe that SilverStone could have squeezed in more caps at its main and modular PCBs). Assuming space was an issue, if fewer electrolytic caps were used there would be enough room for a sufficient number of polymer caps that could filter ripple more effectively. Finally, during the overload test, the 3.3V rail failed to keep its ripple within ATX specs. But because we pushed the PSU beyond its limit, we cannot blame it for this result.
Compared to the higher-capacity SX600-G, the SX500-LG performed much better overall in ripple suppression, as the SX600-G failed to keep ripple on its minor rails inside the ATX specs during the full-load tests. This alone allows the SX500-LG to achieve a higher overall performance score.
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.