Why you can trust Tom's Hardware Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.

Page 8 of 10:

Ripple Measurements

To learn how we measure ripple, please click here.

The following table includes the ripple levels we measured on the ST75F-GS V2's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).

Swipe to scroll horizontally

Test	12 V	5 V	3.3 V	5VSB	Pass/Fail
10% Load	10.4mV	5.4mV	8.1mV	7.1mV	Pass
20% Load	11.8mV	6.5mV	11.2mV	7.7mV	Pass
30% Load	11.6mV	8.3mV	15.5mV	8.8mV	Pass
40% Load	11.3mV	8.3mV	11.5mV	9.4mV	Pass
50% Load	13.2mV	9.5mV	11.8mV	11.0mV	Pass
60% Load	15.0mV	11.3mV	11.5mV	12.2mV	Pass
70% Load	16.8mV	11.4mV	11.9mV	14.0mV	Pass
80% Load	19.2mV	12.1mV	13.8mV	15.9mV	Pass
90% Load	23.7mV	13.1mV	14.1mV	16.9mV	Pass
100% Load	32.8mV	40.5mV	49.9mV	29.3mV	Pass
110% Load	39.3mV	42.9mV	53.5mV	30.6mV	Fail
Cross-Load 1	12.0mV	8.0mV	15.1mV	29.6mV	Pass
Cross-Load 2	33.0mV	42.4mV	51.2mV	24.2mV	Fail

Image 1 of 4

Operating temperature greatly affects ripple suppression under high loads. Up to the 90% load test, the PSU registered low ripple on all of its rails. But during the full load and overload tests, we noticed spikes that hugely affected ripple suppression, especially on the minor rails. After enough test sessions, we found out that if you keep the max operating temperature close to 40 °C (SilverStone's specified ceiling), then ripple suppression is great on all rails. If you push beyond 42 to 43 °C, though, random spikes start showing up.

Since we also tested the unit with 230V, at that input voltage, even at 45 °C and after a prolonged period full-load testing, the ripple on all rails was low. There was no sign of spikes. Apparently, the higher efficiency levels with 230V aren't as stressful, despite the tough conditions.

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.