Bitfenix Whisper Series 550W PSU Review

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Packaging, Contents, Exterior, And Cabling


The box is quite large, despite the PSU's compact footprint. There's a photo of the unit with its fan grille up front, along with a nice Bitfenix badge in the middle. The 80 PLUS Gold icon and a seven-year warranty badge are in the top-right corner. Important technical features are listed in multiple languages on the sides of the box.

As usual, there's a lot of product information on the back side. Bitfenix mentions cable length and connector count, along with the unit's dimensions, power specifications, and the cooling fan's speed throughout the PSU's operational range at 25°C. We would like to see a fan speed graph under more realistic conditions, since 25°C doesn't accurately reflect what you find inside of a PC chassis.


Packing foam is used to protect the PSU inside its box, which might not be eco-friendly but still gets the job done.

Along with the PSU, you get a pouch for storing unused modular cables, several zip ties, a set of screws for mounting the PSU, and a user's manual that's common across all Whisper models.


The external design offers nothing new given its classic appearance. However, the badge in the middle of the fan grille looks really nice. Speaking of that grille, it isn't restrictive, allowing plenty of airflow. Up front, there's a typical honeycomb-style grille, and the small power switch is installed right next to the AC receptacle.

Two large decals adorn the sides, depicting the family name and notably missing model number information.

The modular panel consists of nine sockets, four of which are dedicated to peripheral and SATA cables. The rest are for EPS, PCIe, and ATX connectors.

Attaching the main ATX cable to the PSU's modular socket isn't as easy as it should be. This cable consists of two connectors that are pretty close to each other, and their wiring doesn't give them much flexibility. As you can see in the photo above, the ATX sockets naturally have their connection clips looking at opposite sides to simplify detachment. But the limited flexibility of the ATX connectors and the fact that you should fully twist one of them makes the whole procedure rather tricky, especially if you perform it with the PSU already installed.

The finish is of good quality and its semi-glossy texture doesn't make it a fingerprint magnet.


The main ATX cable features a large plastic cover, under which three polymer caps are hiding: two FPCAPs and a single Chemi-Con. Those caps are used to suppress ripple.

All cables use dark wires and are flat to avoid restricting airflow in your case.

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.