Bitfenix Whisper Series 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 BWG550M's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).

Swipe to scroll horizontally
10% Load12.1mV6.3mV3.4mV5.4mVPass
20% Load17.8mV6.2mV3.7mV6.0mVPass
30% Load18.1mV6.5mV3.7mV5.9mVPass
40% Load17.6mV6.8mV3.7mV8.8mVPass
50% Load17.1mV6.5mV4.1mV11.9mVPass
60% Load19.9mV7.5mV4.7mV13.8mVPass
70% Load19.7mV7.8mV4.8mV18.5mVPass
80% Load19.6mV8.7mV9.2mV24.1mVPass
90% Load18.4mV9.4mV6.3mV25.5mVPass
100% Load18.8mV9.8mV6.7mV22.3mVPass
110% Load19.5mV10.0mV6.8mV22.4mVPass
Cross-Load 119.0mV7.7mV5.1mV3.7mVPass
Cross-Load 217.8mV8.0mV5.3mV20.9mVPass

Ripple suppression is great, especially at 3.3V! CWT offered Bitfenix a great platform, and now the company has a real weapon in its arsenal for infiltrating the competitive PSU market.

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

Contributing Editor

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

  • turkey3_scratch
    Bitfenix did the right thing pairing with CWT here. This is a great unit!
  • Aris_Mp
    Indeed, its performance was a nice surprise for me as well. It's good to see some new competition in this market.
  • Nuckles_56
    Damn, I wonder what Australian pricing will be like for this unit, as I'd be almost tempted to replace my current PSU with a quieter one like this if it is priced well
  • MarekRMac
    Hi, please give me quick advice: Bitfenix Whisper M 550W or Corsair RM550x ?
  • Aris_Mp
    19083753 said:
    Hi, please give me quick advice: Bitfenix Whisper M 550W or Corsair RM550x ?

    Which ever you can find at a lower price. Performance wise they are very close.

  • jonnyguru
    One noticeable difference between the RMx and the Whisper is that the RMx uses an MCU for the fan controller instead of the standard thermistor/transistor circuit in the BitFenix product.