The output voltages ranged within the permitted values for the entire duration of the test period. In particular, the important 3.3 V, 5 V and 12 V voltage rails only deviated by a few millivolts from the nominal values. Only under full load were there slightly increased breaks in voltages, which were again well within the specification.
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Nominal Value
Measurement
Permitted Deviation
3.3 V
3.22 V
3.14 V to 3.47 V
5 V
4.96 V
4.75 V to 5.25 V
12 V
11.88 V
11.40 V to 12.60 V
12 V (CPU)
11.82 V
11.40 V to 12.60 V
5 V (Standby)
4.87 V
4.75 V to 5.25 V
-12 V
-12.51 V
-10.80 V to -13.20 V
Swipe to scroll horizontally
Nominal Value
Measurement
Permitted Deviation
3.3 V
3.28 V
3.14 V to 3.47 V
5 V
5.01 V
4.75 V to 5.25 V
12 V
11.95 V
11.40 V to 12.60 V
12 V (CPU)
11.93 V
11.40 V to 12.60 V
5 V (Standby)
4.90 V
4.75 V to 5.25 V
-12 V
-11.80 V
-10.80 V to -13.20 V
Swipe to scroll horizontally
Nominal Value
Measurement
Permitted Deviation
3.3 V
3.31 V
3.14 V to 3.47 V
5 V
5.05 V
4.75 V to 5.25 V
12 V
11.99 V
11.40 V to 12.60 V
12 V (CPU)
11.98 V
11.40 V to 12.60 V
5 V (Standby)
4.92 V
4.75 V to 5.25 V
-12 V
-11.41 V
-10.80 V to -13.20 V
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I think they'd be great for a digital audio workstation environment now if only there was some more competition in this market segment to drive prices down to a more decent level.
I have read 3-4 other reviews of the zen 400W, and I'm pretty sure there has been no mention of the high pitched sound. It's not a good sign for the zen, but it's probably a faulty powersupply tested in this review.
Without specifying the input voltage, efficiency measurements are pretty useless. Running at 240v will yield a few percent higher efficiency than 120. Even 240v will be more efficient than 220v.
I own the Zen400 power supply and it's exactly what I needed for a quiet HTPC, to the point where it's literally impossible to tell when the PC is on. During normal operation I have never heard the high pitched sound this review mentions (although it did output a sound similar in volume and annoyance to a smoke alarm when I failed to plug in the power cable to the graphics card - it was clearly an error/failure tone).
In regards to the lack of the 8 pin CPU 12v connector, if you can find a motherboard of which the 4 +12v pins of the port are not electrically connected, please point it out to actually justify needing the 8 pin connector. To be honest, a motherboard with a single +12v pin isolated to only 1 or 2 vcore phases would'nt be any motherboard you would want to purchase, for power efficiency reasons.
I agree with the above posters, temps would be nice, and not just of the PSU...
I am quite interested in getting a capable (above 400watt) PSU that doesn't require a fan, but I really need to keep an eye on the temperatures.
I have a fanless mb and vid card (3850 radeon), and would wonder if adding a fanless psu into the mix would jeopardise the system by reducing the air flow through the case. (after all I wouldn't get a fanless PSU if my other components were noisy to begin with!?)
Perhaps an article focused more on configuring a quiet computer (for the purpose of gaming) could be in order?