be quiet! System Power 350W Measurements

Voltage Regulation

+3.3V Regulation/Ripple and Noise
Load Voltage
5% 3.41V (9mV)
10% 3.37V (12mV)
20% 3.36V (14mV)
50% 3.34V (22mV)
80% 3.33V (31mV)
100% 3.31V (35mV)
110% 3.30V (41mV)
Crossload +12V max. +1.52%
Crossload +3.3V/+5V max. +0.00%


+5V Regulation/Ripple and Noise
Load Voltage
5% 5.04V (7mV)
10% 5.03V (13mV)
20% 5.00V (15mV)
50% 4.98V (25mV)
80% 4.97V (33mV)
100% 4.94V (39mV)
110% 4.91V (42mV)
Crossload +12V max. +2.00%
Crossload +3.3V/+5V max. -6.20%


+12V Regulation (Worst Ouput)/Ripple and Noise (Worst Output)
Load Voltage
5% 12.14V (11mV)
10% 12.08V (15mV)
20% 12.05V (19mV)
50% 11.99V (31mV)
80% 11.95V (51mV)
100% 11.87V (59mV)
110% 11.86 V (61mV)
Crossload +12V max. -2.92%
Crossload +3.3V/+5V max. +8.67%

Noise Levels

Sound Pressure Level (Ambient: 16dBA, 1m distance) and Temperatures (Δϑ to 24.2 °C ambient temperature)
Load Opinion
5% 18 dBA (0.5°C)
10% 19 dBA (1.6 °C)
20% 19 dBA (2.5 °C)
50% 19 dBA (3.4 °C)
80% 22 dBA (5.2 °C)
100% 24 dBA (6.4 °C)
110% 24 dBA (8.5 °C)

Efficiency and PFC

Efficiency and Power Factor 115 VAC
Load Efficiency PFC
5% 68.34% 0.872
10% 76.16% 0.902
20% 82.67% 0.926
50% 84.92% 0.938
80% 84.49% 0.942
100% 83.78% 0.949
110% 83.33% 0.957


Efficiency and Power Factor 230 VAC
Load Efficiency PFC
5% 69.49% 0.866
10% 77.75% 0.880
20% 83.21% 0.917
50% 85.86% 0.925
80% 85.58% 0.934
100% 84.52% 0.938
110% 83.73% 0.940

be quiet! is clearly out of ATX specification during the second crossload test while noise and temperatures are low. The 3.3V and 5V rails start slightly above specification during 10% load; they then drop, reaching 3.30V and 4.91V at maximum load. The 12V rails start high at 12.14V and drops to 11.86V with 10% overload. These voltage drops will not cause any problem at all when this PSU is in use in a system.

be quiet! System Power 350W -1 Thermaltake Smart SP-430P 430W -1
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  • pvdw - Wednesday, July 4, 2012 - link

    Here's some good ones to look at in 350W-450W range:

    Seasonic X-400 Fanless
    Seasonic S12II-380
    Silentmaxx Fanless 400W MX460-PFL01
    Nexus Value 430
    Seasonic M12II-430

    And just above the 450W range, but unlikely to use any more power in most systems are these good ones:

    Enermax Modu/Pro87+ 500W
    Kingwin STR-500
  • pvdw - Wednesday, July 4, 2012 - link

    BTW, though I really enjoy most Anandtech articles, your PSU ones can't beat SilentPCReview. But then I can't see how you could do better without an anechoic chamber

    Check out their list of recommended supplies:
  • A5 - Wednesday, July 4, 2012 - link

    The cheapest PSU on that list is well over $100, which is more than double the most expensive one in this article, which is about finding a good "cheap" PSU.

    I'm glad AT did this article as it should encourage a little more competition in the low-end space.
  • knutjb - Wednesday, July 4, 2012 - link

    In my experience I've had a couple low end PSUs do bad things to MBs even though they were modestly loaded. After using a number of different manufacturers all I buy are Seasonics. I get them when they are on sale.

    I have a 9 yr old 600 S-12? on its second system and the output measures the same as it did when new. Blow out the dust occasionally and it just works. Even in low end systems I don't trust inexpensive PSUs, their quality control is all but non-existent with wide variation in samples.

    You get what you pay for and I don't like buying things twice.
  • pvdw - Thursday, July 5, 2012 - link

    A quick search turns up this link:

    The Seasonic S12II 430 for $60 shipped. Or the 380W for $54 shipped.
  • clarkn0va - Friday, July 6, 2012 - link

    Seasonic SS-350ET

    Supposedly not as quiet as their retail offerings, but always inexpensive. I would like to see how this one holds up against similar offerings.

    Maybe AT needs a Bench section for PSUs?
  • Belard - Wednesday, July 4, 2012 - link

    I've bought some CX models for bottom end PCs for clients...

    But I picked up two 500w models, both were defective.

    1) Defective power connector (at the motherboard)...

    2) Flutter fan noises.

    Returned them, bought Thermaltake TR2s.
  • piroroadkill - Wednesday, July 4, 2012 - link

    When the Corsairs first hit the scene, the HX series were all Seasonic.

    Corsair is a nice rebrander, but I go straight to Seasonic for my own system's PSU these days. I have a Seasonic X-660..
  • Arnulf - Wednesday, July 4, 2012 - link

    Great article !

    I wish you could round up even more models and/or present the results in a common bench-like database (you know, like the CPU comparison etc.) where different models coudl be added over time.
  • silverblue - Wednesday, July 4, 2012 - link

    Enermax NAXN ENP450AWT-B 450W - £60 at Scan:
    (Unfortunately, out of stock)

    Rasurbo RAP350 350W - £44 inc. delivery on eBay:

    The 450W variant - £58 inc. delivery on eBay:

    Corsair CX430 V2 430W - from £35 inc. delivery:

    You can find FSP Hexa, Aurum and Fortron PSUs quite easily; the Aurum 80 PLUS Gold 500W is £62 inc. delivery.

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