Super Flower Leadex Gold 550W 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 SF-550F14MG's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).

Swipe to scroll horizontally
10% Load3.8mV7.0mV8.9mV4.2mVPass
20% Load4.4mV7.3mV10.3mV4.3mVPass
30% Load4.8mV7.7mV27.8mV4.5mVPass
40% Load5.2mV7.8mV10.9mV4.6mVPass
50% Load5.5mV7.8mV12.0mV5.0mVPass
60% Load6.1mV8.3mV11.1mV5.0mVPass
70% Load6.1mV8.9mV12.1mV5.3mVPass
80% Load6.9mV9.2mV12.4mV6.5mVPass
90% Load7.1mV9.6mV11.8mV6.5mVPass
100% Load7.8mV10.5mV14.1mV9.9mVPass
110% Load8.4mV10.8mV14.1mV11.0mVPass
Cross-Load 15.8mV8.0mV11.9mV10.1mVPass
Cross-Load 27.9mV10.4mV11.4mV6.4mVPass

Super Flower has proven many times that it is the master of ripple suppression and this Leadex platform clearly shows this. If you want a PSU with super-clean, AC fluctuation-free rails, then this unit is an ideal choice; it's as simple as that.

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 0.01V/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

Contributing Editor

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

  • blazorthon
    Granted the EPS and PCIe wires don't see very high current in most situations (especially the EPS with Haswell or Skylake CPUs), I hardly ever see other PSUs using thinner gauge wires, so I can't imagine it saving enough money to be worth going thinner than the recommended 18 gauge wires most other PSUs have regardless of capacity.
  • Quaddro
    Why crapxon?
    I'm tired to see bulged crapxon..

    If this one use jap caps, it'll be absolutely perfect..
  • iam2thecrowe
    I wonder if it's just a faulty unit with the low hold up time?
  • Mac266
    I wonder if it's just a faulty unit with the low hold up time?

    My first thought too
  • Aris_Mp
    The APFC caps have the advertised capacity so there is nothing wrong with this PSU.
  • mctylr
    Unfortunately, the bridge rectifier's markings are on its hidden side, and we try to avoid desoldering these type of parts since they are extra sensitive to increased heat

    Huh? Since when are bridge rectifiers particularly heat sensitive? I would say that bridge rectifiers are not worth the hassle to desolder, unless you suspect it was an underrated part.

    APFC controller is an NCP1653A provided by ON Semiconductor. It's installed on a small vertical PCB and is covered by insulation tape in order to decrease EMI noise.

    That looks like paper and vinyl / PVC electrical tape wrapped around the vertical PCB, which provides electrical isolation only, I doubt it would make measurable difference in EMI.
  • Aris_Mp
    According to my experience so far they are, unfortunately.

    This provides some EMI protection. There is no need for electrical insulation on this board. As for the degree or EMI protection I can examine this with my EMC probes (once I find the time to do it).
  • Andi lim
    this review said uses a half-bridge topology, I only see one main capacitor. half bridge usualy uses 2 main cap and 2 main switcher right ?
  • Aris_Mp
    the number of APFC caps has nothing to do with the primary topology. However yes half-bridge uses 2 switchers.
  • Andi lim
    You are right, this is half bridge with LLC series resonant converter, nothing wrong with the primary capacitor.