Enermax Revolution SFX 650W PSU Review

Early Verdict

With a lower MSRP, a higher quality fan along with a more relaxed fan profile this would be a much better PSU. We would also like to see a power switch installed along with a larger bulk cap, which would help in increasing the hold-up time which is really low now.


  • +

    Full power at 46°C

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    Ripple suppression (+12V)

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    Load regulation (+12V)

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    Accurate Power Ok signal

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    Fully modular

  • +

    Flat cables

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    SFX-to-ATX adapter & Q-Boom wireless speaker

  • +



  • -


  • -

    Limited airflow to the secondary side

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    Hold-up time

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    Sleeve bearing fan

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    Single EPS connector and 2x PCIe

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    3.3V performance

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    No power switch

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Features & Specifications

For quite some time now, Enermax hasn't had its own production line. So, the company relies on other manufacturers to make its PSUs. Close cooperation with Channel Well Technology is a major advantage for Enermax, since CWT has some very good platforms in its portfolio. On top of that, CWT is able to provide large quantities if/when needed compared to other OEMs with restricted manufacturing capability (Super Flower, for example).

Recently, CWT decided to enter the popular SFX form factor market. Its CSN line consists of five members with capacities ranging from 450W to 650W. Enermax only wanted the two highest-capacity models with 550W and 650W for its for its Revolution SFX family, though.

The Revolution SFX PSUs are 80 PLUS Gold-certified, fully modular, and, according to Enermax, they only use Japanese electrolytic caps. Most of the time, when companies talk about the origin of their capacitors, they're talking about electrolytics, since those are the ones prone to early failure. Polymer caps are more durable, so their origin isn't as important, although Japanese products are still preferred.

The strongest Enermax SFX unit comes with the model number ERV650SWT. Despite its tiny dimensions and high power output, you still get a semi-passive mode. The fan is supposed to start spinning at loads above 30% of the PSU's maximum-rated capacity. At least that's what Enermax claims. In our tests, the fan spun all of the time in environments warmer than 35°C.

Speaking of the fan, it measures 80mm across, whereas competing SFX power supplies use 92mm fans in order to be more quiet. Since many SFX PSUs are used in normal ATX cases, Enermax wisely bundles an SFX-to-ATX bracket. If you need it, that'll save you money and the hassle of ordering another piece of hardware separately. Enermax also drops a small wireless speaker into the ERV650SWT's bundle. We are huge fans of large wireless speakers like the Logitech Boom. But there are also times when it's nice to have something smaller that fits inside of travel bag.


When it comes to efficiency, we're dealing with 80 PLUS Gold and ETA-A certifications. The Cybenetics program's noise rating is LAMBDA-S+, meaning that the PSU lands in a 35-40 dB(A) range and is quite loud. The small fan doesn't help, and this is why 92mm fans able to push more air at lower RPM are preferred in SFX units. Moreover, the fan unfortunately employs a sleeve bearing, which is a budget option with a shorter lifetime than double ball bearing or fluid dynamic bearing fans.

This PSU's temperature rating is 40°C, which we'd expect from such a compact model. At least all of the protection features we could want are supported.

We aren't in love with Enermax's three-year warranty. This is an area where the competition has a big advantage. Corsair's SF line, for instance, is covered by a seven-year warranty. Then again, given the sleeve bearing fan, it wouldn't be wise for Enermax to offer a longer warranty period.

Update, 7/21/17: Enermax informed us that the warranty of the product is actually five years long, although at the moment of the review Newegg lists it with a three-year warranty.

Power Specifications

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Max. PowerAmps18155430.3
Total Max. Power (W)650

The minor rails are set at 100W combined, while the +12V rail can deliver the PSU's full power on its own. The 5VSB rail is also strong enough to meet a modern system's demands.

Cables And Connectors

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Modular Cables
DescriptionCable CountConnector Count (Total)Gauge
ATX connector 20+4 pin (300mm)1118AWG
4+4 pin EPS12V (400mm)1118AWG
6+2 pin PCIe (400mm) 2218AWG
SATA (200mm+150mm+150mm)2618AWG
4-pin Molex (250mm+150mm+150mm+150mm)1418AWG

There is only one EPS connector, and the number of PCIe connectors is also limited to two. Really, a 650W PSU could easily support up to two strong graphics cards with a couple of auxiliary power connectors each, so we'd like to see more of that connectivity.

On the other hand, the number of SATA and four-pin Molex connectors is sufficient for this form factor.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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Contributing Editor

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

  • shrapnel_indie
    How many motherboards require more than one EPS connector in the entry to enthusiast level motherboards (excluding server boards)? How many server boards? How many enthusiasts actually use server boards?

    IMHO, if a PSU has 1 or 2 EPS connectors shouldn't be a pro or con as the vast majority of boards used from entry level to enthusiast only really requires one connector. Server boards are a different matter. IMHO, just making a clear note how many EPS connectors should be good enough.
    I can see wanting more than 2 PCIe of course, but how many SFX models come with 2 EPS? How many dual CPU micro atx mobos are there anyway?
  • Ne0Wolf7
    Why would you ever want there not to be a power switch? I use mine all the time... It seems like such a simple thing to add too.
  • 10tacle
    ^^That's the first thing I noticed in the pictures. I use mine on occasion too, especially when getting lockups during overclock testing. Flicking a switch is a lot more convenient than reaching around and unplugging and making sure the cable doesn't fall down behind the desk causing colorful four letter language. Unwise omission that is inexcusable in this category of PSU. I would rule out this PSU just for that omission alone.

  • Aris_Mp
    about the two EPS connectors, most mid to high-end mainboards use one EPS and one ATX12V (so they need two CPU connectors) especially the new ones. Why not have this option and be restricted to mainstream mainboards. Not only server or dual CPU mainboards require two EPS connectors.
  • Marcus52
    Enermax still hasn't recovered their quality since they shut down their own production facilities, which is a real shame, they used to be one of the best.
  • superflykicks03
    You guys literally have ads that play over the top of your intrusive popup videos. You literally have to watch a 30 second ad before you get to watch the unwanted video :/ Not exactly user friendly. I know I know revenue blah blah, and just get a popup blocker yadda yadda.
  • maxwellmelon
    Why would you turn off the power on the power supply on computer lockup. Just hit the reset switch. I would venture to say 9 out of 10 people could care less as there pc is always on.
  • 10tacle
    Because hitting reset from the case button does not guarantee a solid reboot. On my system anyway.
  • warmon6
    For an SFX psu, not having a power switch on the PSU doesn't bother me to much.

    Depending on the case design (like my rvz01), you couldn't access the psu without taking the computer apart to access that switch. So unplugging the computer or holding the power button for 5 seconds would be a lot faster.

    Now if this was an ATX PSU i would give a bit more care for as it's extremely rare for an ATX psu to be placed somewhere else inside the case that cant be access from the outside.


    I do have to ask though, does your computer lock up so much that even holding the case power button for the 3 to 5 seconds does nothing?

    Most computers I've messed with seems to be able to power off fully even when there is a hard lockup doing that method.

    But i do agree with you about that hitting a reset doesn't guarantee a solid reboot. Certainly when trying to dial in overclock settings.