Bitfenix Whisper Series 550W PSU Review

Cross-Load Tests And Infrared Images

Our cross-load tests are described in detail here.

To generate the following charts, we set our loaders to auto mode through our custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V and 3.3V rails. The load regulation deviations in each of the charts below were calculated by taking the nominal values of the rails (12V, 5V and 3.3V) as point zero.

Load Regulation Charts

Efficiency Chart

This is one of the most efficient 550W Gold-rated PSUs we have ever tested. Its best spot is between 175W and 270W, where it delivers over 92% efficiency when the minor rails stay below 25W combined load. The BWG550M is able to exceed 90% efficiency for a much wider range, starting from around 90W to 450W.

Ripple Charts

Infrared Images

Toward the end of the cross-load tests, we took some photos of the PSU with our modified FLIR E4 camera that delivers 320x240 IR resolution (76,800 pixels).

Thanks to increased efficiency, temperatures inside the PSU remain low.

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  • 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
    2391142 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.