Bitfenix Formula Gold 650W PSU Review

Early Verdict

The BF650G offers silent operation along with great performance and it has an affordable price tag. The cherry on top is its super compact dimensions, which will compensate, in a degree at least, the lack of modular cables since the smaller a PSU's footprint the easier its installation. Bitfenix is on the right path in the tough PSU market and hopefully it will keep following it.


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    Full power at 46°C

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    Ripple suppression

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    Load regulation (minor rails)

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    Hold-up time

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    Accurate Power Ok signal

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    Transient response

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    Build quality

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    2x EPS & 4x PCIe connectors

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    Compact dimensions


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    Inrush current (230V)

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    PF is a little lower than normal

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Features & Specifications

After the success of its Whisper PSU family, BitFenix is following up with a more affordable Formula Gold line-up. Currently, there are four models in this series with capacities ranging from 450W to 750W. They all feature 80 PLUS Gold and ETA-A efficiency. When it comes to noise, Cybenetics gives the 450W and 550W models LAMBDA-A++ (<15 dB[A]) ratings, while the 650W and 750W units achieve LAMBDA-A+ (15 to 20 dB[A]) acoustic readings.

Today, we're reviewing the Formula Gold family's second-strongest product, the BF650G, which offers enough capacity to power a mid-range gaming system.

Like the other Formula Gold units, BitFenix's BF650G features compact dimensions, thanks to a 14cm depth measurement. Increasingly, OEMs are trying to shrink their PSUs in an effort to simplify installation. We don't have a problem with this downsizing, so long as it doesn't affect performance or noise. Naturally, lower-capacity models can be miniaturized more easily than higher-capacity ones, which tend to run hotter and require more cooling. In our opinion, though, no PSU's performance should be compromised in the name of a smaller footprint, and the same applies to acoustics. Back in the day, most of us didn't have a problem with loud PCs, so long as they were fast. But as the years passed and efficiency took center stage, noisy components became oddities. Quiet operation is a huge advantage, and PSUs play a significant role in keeping overall noise output low, especially under taxing workloads.


The BF650G's temperature rating for full power output is specified at 40°C, and the PSU includes all of the protection features you could possibly want.

Its 120mm fan uses a rifle bearing, which is an enhanced version of the sleeve bearing. The fan is driven by a relaxed speed profile, so it's very quiet, even under tough conditions. There is no semi-passive mode, which we don't consider an issue since the fan spins so slowly under light loads anyway.

Finally, BitFenix's five-year warranty is satisfactory in light of its $80 price tag.

Power Specifications

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Max. PowerAmps2020252530302.50.3
Total Max. Power (W)650

There are four +12V rails, two of which offer higher current output than the others. The minor rails are limited to 100W of maximum combined power (at least on paper, since OCP on those rails is much higher), while the 5VSB rail has the capacity we'd expect from a modern PSU.

Cables & Connectors

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Captive Cables
DescriptionCable CountConnector Count (Total)GaugeIn Cable Capacitors
ATX connector 20+4 pin (650mm)1118-22AWGYes
4+4 pin EPS12V (670mm+150mm)1218AWGNo
6+2 pin PCIe (570mm+150mm)2418AWGNo
SATA (500mm+150mm+150mm+150mm)1418AWGNo
SATA (500mm+150mm) / Four-pin Molex (+150mm+150mm)24 / 418AWGNo
AC Power Cord (1400mm) - C13 coupler1118AWG-

It is nice to see an affordable, mid-capacity PSU with a couple of EPS connectors. Four PCIe connectors allow the BF650G to handle a couple of potent graphics cards, while eight SATA connectors are more than enough for any mid-range system. There is also a quartet of four-pin Molex connectors exposed across two cables. You don't get a FDD connector, though, which we're not bothered by. Use an adapter if you really need one.

Power Distribution

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Power Distribution
12V1ATX, Peripheral, SATA

There are four +12V rails, two of which have higher OCP than the other two. The first +12V rail (12V1) feeds a 24-pin ATX connector, along with the peripheral connectors. The EPS connector is handled through 12V2, while 12V3 and 12V4 power a couple of PCIe connectors each. All in all, BitFenix's power distribution is optimal.

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Contributing Editor

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

  • Dark Lord of Tech
    Great Review..Thanks!
  • turkey3_scratch
    Man this one is great! Thanks for the review, I appreciate the hard work you put into them.
  • Lutfij
    Was a great read for the weekend and an interesting one too. Keep up the good work Aris! ;)