Bitfenix Whisper Series 550W PSU Review

Bitfenix recently released its Whisper PSU family, which, as it name implies, promises quiet operation. This review focuses on the 550W model, offering 80 PLUS Gold efficiency and fully modular cabling.

By Aris Mpitziopoulos
published

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Protection Features, Evaluated

Check out our PSUs 101 article to learn more about PSU protection features.  

Our protection features evaluation methodology is described in detail here.

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Protection Features
OCP12V1: 35.6A (142.4%) 12V2: 36.0A (144%) 12V3: 38.2A (127.3%) 5V: 28.0A (140%) 3.3V: 29.75A (148.75%) 5VSB: 4.6A (184%)
OPP721.51W (131.18%)
OTPYes (>130°C @ +12V heat sink)
SCP12V: Yes 5V: Yes 3.3V: Yes 5VSB: Yes -12V: Yes
PWR_OKOperates properly
NLOYes
SIPSurge: MOV Inrush: NTC Thermistor & Bypass Relay

Because we didn't see excess ripple or lousy load regulation, it's fairly safe to conclude that OCP is configured properly on all rails. The OPP triggering point looks to be a little higher than usual, though the PSU doesn't have a problem delivering over 720W of power subjected to normal operating temperatures.

This platform features over-temperature protection, which is set quite high since the unit is rated at 50°C for continuous full load delivery. Moreover, SCP is present on all rails and the power-good signal provides accurate information to the system. Finally there is a MOV (Metal Oxide Varistor) in the transient filtering stage for protection against spikes, while the inrush current protection consists of an NTC thermistor and a bypass relay.

Aris Mpitziopoulos
Aris Mpitziopoulos
Contributing Editor

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

6 Comments Comment from the forums
  • turkey3_scratch
    Bitfenix did the right thing pairing with CWT here. This is a great unit!
    Reply
  • Aris_Mp
    Indeed, its performance was a nice surprise for me as well. It's good to see some new competition in this market.
    Reply
  • 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
    Reply
  • MarekRMac
    Hi, please give me quick advice: Bitfenix Whisper M 550W or Corsair RM550x ?
    Reply
  • 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.

    Reply
  • 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.
    Reply