Seasonic X Series 750 W Review

Name: Seasonic X Series 750 W
Brand: Seasonic

crmaris

on Dec 27th, 2012,

in Power Supplies.

Manufacturer: Seasonic

Performance Rating & Performance per Dollar »

Ripple Measurements

You will see the ripple levels that we measured on the main rails of the X-750 in the following table. The limits are, according to the ATX specification, 120 mV (+12V) and 50 mV (5V, 3.3V, and 5VSB).

Ripple Measurements Seasonic X-750
Test	12 V	5 V	3.3 V	5VSB	Pass/Fail
20% Load	23.9 mV	13.0 mV	11.5 mV	4.4 mV	Pass
40% Load	29.3 mV	13.1 mV	12.2 mV	5.6 mV	Pass
50% Load	28.9 mV	13.2 mV	12.3 mV	6.3 mV	Pass
60% Load	30.4 mV	13.3 mV	12.3 mV	6.6 mV	Pass
80% Load	34.3 mV	14.6 mV	12.9 mV	7.3 mV	Pass
100% Load	39.0 mV	16.6 mV	14.1 mV	8.6 mV	Pass
110% Load	42.3 mV	18.0 mV	14.2 mV	9.3 mV	Pass
Crossload 1	25.1 mV	15.2 mV	13.5 mV	22.4 mV	Pass
Crossload 2	38.8 mV	14.2 mV	13.1 mV	23.4 mV	Pass

Ripple suppression is very good, although the +12V rail registered, at worst, almost 40 mV ripple. This is, of course, a low reading, and we wouldn't even mention it if this PSU weren't made by Seasonic, but they already spoiled us with their top-performing products, so we expect to see under 30 mV ripple on this rail (we know we are very picky right now, but we just can't help it). Strangely enough, the AX760, which is based on the same platform with some minor changes, registered 25.6 mV ripple on the +12V rail at full load, which is a noticeable lower reading if compared to the X-750's result. Finally, ripple suppression on the minor rails is simply excellent.

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. We set 0.01 V/Div (each vertical division/box equals 0.01 V) as standard for all measurements.