Zalman ZM1000-EBT 1000 W Review

Name: Zalman ZM1000-EBT 1000 W
Brand: Zalman

crmaris

on Oct 20th, 2015,

in Power Supplies.

Manufacturer: Zalman

EMC Pre-Compliance Testing »

Ripple Measurements

You will see the ripple levels we measured on the ZM1000-EBT's rails 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 - Zalman ZM1000-EBT
Test	12 V	5 V	3.3 V	5VSB	Pass/Fail
10% Load	16.9 mV	8.2 mV	13.2 mV	9.2 mV	Pass
20% Load	22.3 mV	7.9 mV	15.7 mV	8.5 mV	Pass
30% Load	26.2 mV	8.0 mV	14.2 mV	9.3 mV	Pass
40% Load	31.6 mV	8.4 mV	15.0 mV	11.1 mV	Pass
50% Load	37.1 mV	9.6 mV	19.3 mV	13.9 mV	Pass
60% Load	41.3 mV	10.6 mV	23.4 mV	15.8 mV	Pass
70% Load	46.4 mV	10.8 mV	24.5 mV	18.3 mV	Pass
80% Load	53.5 mV	12.3 mV	28.8 mV	20.6 mV	Pass
90% Load	58.0 mV	12.8 mV	30.7 mV	22.5 mV	Pass
100% Load	64.3 mV	16.6 mV	38.9 mV	25.9 mV	Pass
110% Load	70.4 mV	17.7 mV	40.2 mV	28.2 mV	Pass
Crossload 1	29.6 mV	12.9 mV	26.7 mV	9.8 mV	Pass
Crossload 2	61.3 mV	14.7 mV	30.7 mV	26.7 mV	Pass

Given the quality of the capacitors, some would expect better ripple suppression. However, Japanese capacitors alone cannot work miracles as the design isn't optimal. The quality of caps mostly plays a key role when it comes to the performance over time. Taiwanese or even some Chinese caps might offer good initial performance, but they will age faster than Japanese caps of good quality, which will cause their performance to falter over time.

The +12V rail didn't perform as well as those of the high-end category; however, the PSU belongs to the budget category, so its 65 mV ripple at full load and at a very high ambient temperature doesn't actually look bad. The 5V rail performs very well, the 5VSB rail's ripple suppression is good-enough, and there is lots of room for improvement on the 3.3V rail. While not a ripple-proof platform, its ripple suppression won't cause any problems either.

Ripple at Full Load

You can see the AC ripple and noise the main rails registered (+12V, 5V, 3.3V, and 5VSB) in the following oscilloscope screenshots. 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 the standard for all measurements.