be quiet! SFX L Power 600W PSU Review

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Ripple Measurements

To learn how we measure ripple, please click here.

The following table includes the ripple levels we measured on the SFX L Power 600W's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).

Swipe to scroll horizontally
10% Load8.1mV8.0mV11.9mV6.0mVPass
20% Load10.7mV9.2mV14.0mV7.8mVPass
30% Load13.7mV11.0mV17.7mV8.8mVPass
40% Load17.3mV12.1mV18.6mV10.1mVPass
50% Load22.0mV14.6mV19.6mV11.7mVPass
60% Load27.6mV16.1mV21.7mV13.5mVPass
70% Load30.3mV17.8mV25.5mV15.3mVPass
80% Load36.1mV20.2mV27.6mV16.8mVPass
90% Load40.0mV21.4mV30.1mV19.2mVPass
100% Load45.9mV23.6mV31.9mV21.3mVPass
110% Load57.4mV25.2mV35.8mV23.8mVPass
Cross-Load 114.1mV13.7mV18.7mV11.1mVPass
Cross-Load 252.8mV21.9mV30.2mV18.8mVPass

Ripple suppression on the +12V and 3.3V rails is average, while it's fairly good on the 5V and 5VSB rails. We would like to see below 40mV ripple at +12V under full load, and close to 25mV at 3.3V under the same conditions.

Ripple Oscilloscope Screenshots

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

Ripple At Full Load

Ripple At 110-Percent Load

Ripple At Cross-Load 1

Ripple At Cross-Load 2

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Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • reghir
    Not sure take a look at NewEgg reviews which show 3 users reporting DOA units
  • AC____
    How does it compare to Corsair's?
  • Aris_Mp
    The SF600 has higher performance. This is shown in the relative performance chart. However in the overall noise score the SF600 is much higher as well, because its fan profile gets highly aggressive once you load its minor rails. In real life conditions where the minor rails are lightly used, it is quite silent.
  • Aris_Mp
    DOA can happen for several reasons, with hard shipping conditions being one of them.
  • expert_vision
    You know what baffles me? How is it possible that no monitoring is offered in today PSUs ? I used to have a HighPower PSU 10 years ago that had a simple 7 segment display, showing instantaneous power draw in watts, and a 3 header pin for FAN RPM. You'd think by today that would be standard. But no, instead they put freaking RGB in everything ...
    Too expensive when you cheap out on a 85C primary cap.
  • below
    I had bought one of them a few weeks ago and after installing in bitfenix portal case it has start to randomly make noises. I had rebuild my block two times just to make sure that there is nothing except PSU fan itself making that noise. The noise is comparably with very old HDD's or even Floppy crunching, its super annoying and only appears in PSU working state (when fan at the bottom) and mostly on high load, also noise could be very loud

    Also I have found some review on Spanish (I think) from amazon about this PSU and customer have exactly the same issue, so looks like it could be design problem.
    This PSU is a winner of most comparisons an reviews everywhere and I very dissapointed that none of reviewers couldn't find such awfull issue for quiet PSU.

    Also it should be a shame for company named 'be quiet' that it's 'silent wings' in that PSU making that horrible noises.