Hot Test Results

Even though they complied with the design power quality guidelines, earlier SFX PSU designs displayed poor power quality figures. More recent models, like the powerful SilverStone SX700-LPT that we reviewed last year, were greatly improved.

The Enermax Revolution SFX also delivers good voltage regulation and reasonable power quality figures. Voltage regulation on the 3.3V/5V lines is at about 2.2%, with the 12V line doing much better and maintaining a regulation of 1.5% within the nominal load range. Filtering is good on the 12V line, with our instruments recording a maximum voltage ripple of only 30 mV under maximum load. This figure is exceptional and comparable to that of the best ATX PSUs, yet the designer seems to have neglected the 3.3V and 5V lines, the filtering of which is much worse. The 3.3V and 5V lines recorded a maximum of 30 mV and 38 mV respectively with the PSU nominally loaded. With the PSUs voltage lines cross-loaded, the 5V line almost reached the design limit of 50 mV.

Main Output
Load (Watts) 131.34 W 326.08 W 487.26 W 646.35 W
Load (Percent) 20.21% 50.17% 74.96% 99.44%
  Amperes Volts Amperes Volts Amperes Volts Amperes Volts
3.3 V 1.64 3.37 4.09 3.36 6.13 3.33 8.18 3.3
5 V 1.36 5.07 3.41 5.02 5.11 4.99 6.82 4.96
12 V 9.82 12.11 24.54 12.03 36.81 11.99 49.08 11.93


Line Regulation
(20% to 100% load)
Voltage Ripple (mV)
20% Load 50% Load 75% Load 100% Load CL1
3.3V + 5V
3.3V 2.1% 16 20 22 30 20 38
5V 2.2% 18 22 28 38 28 48
12V 1.5% 20 24 26 30 34 26

The energy conversion efficiency of the Revolution SFX 650W PSU takes a major hit with the unit operating inside our hotbox, suggesting that the small PSU is heavily thermally stressed. The cooling fan once again started when the load was above 150 Watts and the internal temperatures got uncomfortably high, yet not to the point that the thermal protection of the PSU would kick in. The average efficiency reduction is 2.3%, with a drop of 2.6% at 100% load, suggesting very high thermal stress.

Once again, the small cooling fan started when the PSU’s load had almost reached 200 Watts. Initially the noise levels are relatively low, yet this time the fan’s speed increases exponentially in relation to the load, with the small fan struggling to provide enough airflow for the PSU to remain operational. Although it manages to do so, the noise coming from the fan when the load is above 400 Watts is overwhelming, with a high-pitch whine that would probably be audible even through headphones. This clearly is not a typical everyday use scenario and is unlikely that the PSU will survive such abuse for prolonged periods of time, but it will remain operational under very adverse conditions should it need to. 

Cold Test Results Final Words & Conclusion
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  • jrs77 - Friday, June 30, 2017 - link

    SFX-L is the way to go, as these regular SFX-PSUs do struggle with thermal issues due to the small 80mm fan used.
    I have two Silverstone SFX PSUs. One 450W with 80mm fan and one 500W SFX-L with a 120mm fan. The difference in temperatures and noise-levels is huge.
  • Alistair - Friday, June 30, 2017 - link

    Should try the Corsair 450W SFX power supply. It is my most satisfying purchase ever. No need for SFX-L.
  • nijimon - Monday, July 3, 2017 - link

    Agreed, the 92mm fan on the Corsair doesn't spin at system idle on my rig (Haswell i5, 2 SSDs, 1 HDD, RX470 and WiFi card on a Mini ITX mobo). It will make noise during gaming, but every fan is spinning by then, it will however spin down when the load drops unlike what I read about the Silverstone units. There is also a 600W version.
  • DanNeely - Friday, June 30, 2017 - link

    While dual gpu is unlikely in the systems this is likely to be used with. 2x 8pin connectors can run a pair of 225w cards. Combined with a full power desktop CPU and 80% load seems doable even without an overclock.
  • prateekprakash - Saturday, July 1, 2017 - link

    I have an Enermax Revolution SFX 650 power supply in an NCASE M1.

    One sata power cable with 3 sata power points is being used to power 4 things:
    1. An 8 TB 3.5" HDD
    2. A 5 TB 2.5" HDD
    3. A Swiftech 8 way PWM Fan splitter
    4. An EK XTOP REVO D5 PWM Plexi Pump.

    I am using a "SATA converts to right angle SATA + molex pin" adapter to split one of the SATA power points between fan splitter and the pump.

    My question is, is the SATA power cable sufficient to supply the power, or am I at risk?

    For your reference, the SATA power cable is modular with 6pin pcie looking connector on the PSU side.(which in my guess would be able to supply 75 watts, wouldn't it?)

    I went this route because the pump needs a molex connector, and adding the molex cable would be quite messy inside the case, especially because I have a custom cpu + GPU water loop in there with a 240 rad.
  • prateekprakash - Saturday, July 1, 2017 - link

    Also, in my case the psu fans keeps spinning even when the desktop is idling, sipping ~70watts. Perhaps because of the higher temps (ambient temperature is ~28° here)... I was quite disappointed because I expected it to be in fanless mode all the time (my config is i7 6700, gtx 1060, 1 3.5" HDD, 1 2.5" HDD, 1 D5 Pump, and I measured ~170w from the wall in unigine heaven and max 224w in FIFA 17 demo)
  • HomeworldFound - Saturday, July 1, 2017 - link

    You're fine with that build. Your pump is going to run at 37w maximum and you don't need to run it anywhere near full speed. Keeping your power supply fan running in that build would be beneficial anyway.
  • nwarawa - Wednesday, July 5, 2017 - link

    Sleeve bearing fan? Instant fail. I would rather have some decent middle-ground capacitors like Teapo if it meant getting a at least modified sleeve bearing (rifle,etc). It's an unbalanced design. Anything over $50, there is no excuse.

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