Seasonic G Series 550 W Review

Name: Seasonic G Series 550 W
Brand: Seasonic

crmaris

on Oct 1st, 2012,

in Power Supplies.

Manufacturer: Seasonic

Performance Rating & Performance per Dollar »

Ripple Measurements

In the following table, you will see the ripple levels that we measured on the main rails of the G-550. According to the ATX specification, the limits are 120 mV (+12V) and 50 mV (5V, 3.3V, and 5VSB).

Ripple Measurements Seasonic SSR-550RM
Test	12 V	5 V	3.3 V	5VSB	Pass/Fail
20% Load	8.4 mV	4.8 mV	5.6 mV	8.1 mV	Pass
40% Load	13.7 mV	5.3 mV	5.8 mV	10.6 mV	Pass
50% Load	16.1 mV	5.5 mV	5.9 mV	11.9 mV	Pass
60% Load	18.7 mV	5.8 mV	6.1 mV	12.2 mV	Pass
80% Load	23.1 mV	6.1 mV	7.1 mV	14.3 mV	Pass
100% Load	30.7 mV	8.1 mV	9.7 mV	16.4 mV	Pass
110% Load	36.3 mV	9.9 mV	9.2 mV	17.0 mV	Pass
Crossload 1	10.6 mV	6.5 mV	7.3 mV	15.9 mV	Pass
Crossload 2	31.0 mV	7.8 mV	8.0 mV	14.5 mV	Pass

Ripple suppression is excellent on all rails, something typical for a Seasonic PSU. Even with 110% load, ripple is kept well under control. The most impressive results are registered by the minor rails which don't exceed 10 mV in any case!

Ripple at Full Load

In the following oscilloscope screenshots, you can see the AC ripple and noise that the main rails registered (+12V, 5V, 3.3V, and 5VSB). The bigger the fluctuations on the oscilloscope's screen, the bigger the ripple/noise. For all measurements, we set 0.01 V/Div (each vertical division/box equals to 0.01 V) as standard.