Be Quiet! Straight Power E8 400 W Review

Name: Be Quiet! Straight Power E8 400 W
Brand: be quiet!

crmaris

on Jun 20th, 2011,

in Power Supplies.

Manufacturer: be quiet!

Value & Conclusion »

Ripple Measurements

In the following table you will find the ripple levels that we measured on the main rails of SP-E8 400W. According to ATX specification the limits are 120 mV (+12V) and 50 mV (5V & 3.3V).

Ripple Measurements
Test	12 V	5 V	3.3 V	Pass/Fail
20% Load	20.2 mV	14.6 mV	11.4 mV	Pass
40% Load	39.6 mV	26.4 mV	22.8 mV	Pass
50% Load	34.8 mV	11.2 mV	11.0 mV	Pass
60% Load	41.4 mV	17.8 mV	17.2 mV	Pass
80% Load	53.8 mV	27.2 mV	24.2 mV	Pass
100% Load	67.2 mV	18.4 mV	16.2 mV	Pass
Crossload 1	47.2 mV	25.2 mV	23.4 mV	Pass
Crossload 2	65.2 mV	19.8 mV	15.4 mV	Pass

Ripple/noise suppresion overall is decent with the maximum readings at each measured rail reaching about the half of the ATX limit. However the minor rails showed some strange behaviour with 40% and 80% load where ripple registered an unproportional increase.

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). 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 to 0.01V) as standard but sometimes we are forced to use 0.02 V/Div, meaning that the fluctuations will look smaller but actually this wont be the case.