Corsair RM Series 850 W Review

Name: Corsair RM Series 850 W
Brand: Corsair

crmaris

on Sep 29th, 2013,

in Power Supplies.

Manufacturer: Corsair

Performance Rating, Performance per Dollar & Noise Rating »

Ripple Measurements

You will see the ripple levels we measured on the main rails of the RM850 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 Corsair RM850
Test	12 V	5 V	3.3 V	5VSB	Pass/Fail
20% Load	12.5 mV	11.7 mV	12.6 mV	13.0 mV	Pass
40% Load	15.4 mV	18.1 mV	14.8 mV	13.6 mV	Pass
50% Load	19.2 mV	21.2 mV	15.3 mV	12.7 mV	Pass
60% Load	19.6 mV	16.8 mV	15.8 mV	14.7 mV	Pass
80% Load	25.7 mV	28.4 mV	14.2 mV	14.9 mV	Pass
100% Load	37.8 mV	33.3 mV	21.9 mV	17.1 mV	Pass
110% Load	41.6 mV	36.8 mV	24.3 mV	18.7 mV	Pass
Crossload 1	16.0 mV	19.9 mV	25.2 mV	9.6 mV	Pass
Crossload 2	33.8 mV	22.7 mV	16.9 mV	17.6 mV	Pass

Ripple suppression on all rails but 5V was pretty good, though definitely not among the best we have ever seen. Now, on the 5V rail there is room for improvement, and we would like to see a reading below 30 mV, ideally close to 20 mV, like we saw on the 3.3V rail. However, ripple suppression on the +12V rail is what matters the most and a reading below 40 mV at full load is a good result, with readings below 20 mV belonging to the "awesome" category.

Ripple at Full Load

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