To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the Hydro X 450's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).
Ripple suppression is satisfactory on the +12V rail and good on the minor rails (5V and 3.3V). At 5VSB, ripple is a little higher compared to the other rails. But it's still much lower than the corresponding limit. Moreover, this rail just isn't that important. As long as its ripple doesn't exceed 50mV, you have nothing to worry about.
In general, the HGX450 demonstrates good ripple performance. And thanks to its Japanese electrolytic caps, this performance should remain at the same levels on the long run. PSUs with lower-quality caps, even if they offer high performance initially, age more quickly, causing performance to take a hit over time.
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.