Silent Running: Two Fanless Power Supplies And A Quiet One, Tested

Measurements: SilverStone SST-ST50NF

Efficiency, According to the 80 PLUS Specification

Efficiency Across the Power Spectrum

The 80 PLUS Bronze efficiency requirements aren't as stringent. So, while the SST-ST50NF does meet the organization's Bronze-level requirements, its efficiency value at low loads is far worse than the values recorded from the other two contenders. At 25 W, its efficiency is only 60%. With that said, it behaves like a typical Bronze-certified power supply, and does not stand out negatively among other Bronze-level supplies.

Unfortunately, the same cannot be said about the ripple voltage on its +12 V rail. At 129 mV, it does not even comply with ATX standards.

On the positive side, the SST-ST50NF sports an above-average hold-up time of more than 40 ms. The Nightjar power supply passes all other tests with flying colors. We measured a temperature increase of 49 degrees Fahrenheit, which is slightly less than the temperature increase of the Seasonic supply. Also, we're fans of the warning LED on the back of the power supply that warns of critical internal temperatures (though we're not sure you'd see it light up behind your PC).

A Peek at the PCB

The first thing we noticed after opening SilverStone's SST-ST50NF was its massive heat sinks covering large parts of the circuit board. This is a stark contrast to the Seasonic X-460.

Obviously, the dramatically larger heat sinks are necessary in light of the Nightjar's lower efficiency rating. At an identical load, it'll dissipate more heat than the 80 PLUS Gold-certified Seasonic unit. We can also see that the SilverStone supply has a well-designed input filter, unlike some low-cost solutions. SilverStone also uses premium-grade components, like Chemi-Con capacitors from Japan and Infineon MOSFETs. Instead of a single high-capacitance capacitor on the primary circuit, four smaller ones are used in parallel, which increases the surface area and thus aids in cooling. Copper shims between the power transistors and the large heat sink also serve to improve cooling.

The manufacturing quality of this fanless supply is impeccable, and the quality of the electronic parts is top-notch as well. However, the out-of-tolerance ripple voltage does raise questions about the electrical quality of this power supply. When we factor in the lower price and higher efficiency of competing models, like Seasonic's X-460, we find it difficult to recommend the fanless solution from SilverStone.

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  • s3anister
    zeratul600Why does americans are so picky about the noise rate??? i never stop to think about that! it has never become an obstacle to enjoy my pc experience

    Last time I checked, Americans aren't the only ones who enjoy a silent computing experience...
  • amuffin
    zeratul600Why does americans are so picky about the noise rate??? i never stop to think about that! it has never become an obstacle to enjoy my pc experience

    Many companies that are focused on silence such as Noctua and beQuiet! are not "American."
  • Other Comments
  • amuffin
    Seasonic, me gusta :)
  • zeratul600
    Why does americans are so picky about the noise rate??? i never stop to think about that! it has never become an obstacle to enjoy my pc experience
  • the1kingbob
    Fan noise has never bothered me much, which maybe why I own two 4870s... one of which has a jet plane I mean reference cooler on it..... sadly my wife doesn't care much for the noise, which lead me to buy her wireless headphones :)

    I think it is quite neat that they have fanless option. I would never take the risk, but if I did I would chose seasonic, my 750W has done me well.
  • s3anister
    zeratul600Why does americans are so picky about the noise rate??? i never stop to think about that! it has never become an obstacle to enjoy my pc experience

    Last time I checked, Americans aren't the only ones who enjoy a silent computing experience...
  • amuffin
    zeratul600Why does americans are so picky about the noise rate??? i never stop to think about that! it has never become an obstacle to enjoy my pc experience

    Many companies that are focused on silence such as Noctua and beQuiet! are not "American."
  • Deemo13
    I didn't know they made fanless power supplies....cool beans.
  • uruquiora
    Seasonic for the win :)
  • mesab66
    ZERTUL600......FOR THE VAST MAJORITY OF FOLKS, PERSISTANT/RELENTLESS NOISE QUICKLY BECOMES VERY ANNOYING!!..........give 100 folk a choice of 2 pc rooms - one near silent and one, noisy as hell. Riddle me this....how many go for the quiet room?
    --> argument over.
  • mitko
    A year ago I built a water cooled system with an i7 2600k and 2 x Radeon 6990. The whole point of the water cooling was to make things extra quiet, which it did, except for the power supply. I tried two different Corsair AX1200 units before switching to a Nexus RX1100. The power supply is still BY FAR the noisiest component in the computer. Does anyone have a suggestion how to reduce the noise? I could not find any currently manufactured water cooled PSUs. Do you think it is possible to use 2 low-noise PSUs to power components on the same motherboard? Any other ideas are also welcome. I need at least a 1100W PSU, as I've actually measured the power consumption to be 1067W at 100% CPU and GPU load.

    For the record I am not an American and I don't live in the US :)
  • belardo
    In a quality modern PSU... can anyone really hear the PSUs?

    I've been buying Corsair and even $45 Thermaltake 500... and I cannot hear them... with the cover open. The problems with FANLESS PSUs and GPUs is that they become heat-sinks... sure they are quiet, but everything around them gets warm. You need to blow the hot air out.

    Going from a fanless GPU to something with a huge fan (H.I.S. brand) - the fans barely makes noise and use a rear exhaust and I can run the system fans at a lower speed.


    Mitko: get soundproofing material, apply to inside of case. Put case on floor.

    My case is on the desk, a foot or so away from me... its no louder than the A/C vent blowing air in the room.
  • jassenjj
    There are some things to consider with fanless PSUs:
    1. The heat stress is the factor No. 1 for the lifespan of the capacitors, no matter if they are conductive polymer or very high quality electrolytic brand.
    2. The case should use more higher intake flow to make sure that the power supply's heat does not enter the case.
    3. A noise level of 10-13 dB can be tolerated for the sake of sustainability and avoiding the risk of heating up your case with the heat from from the PSU.

    Personally, in the last 10 years I admire Seasonic for their stile... But I would use a passive solution that is still in the PC case just for a while.
  • razor512
    the main difference with a silent PSU is the capacitor rating. Most noise ones use 1000 hour 105C capacitors, while a high end silent one will use caps that are in the range of 10,000 hour 105c, or even 125c

    most of the voltage regulators are mostly the same though they may add a larger heatsink on them.

    you could pretty much turn a standard PSU into a silent one by swapping the caps and heatsinks. High quality capacitors are about 3-5 times more expensive (may take the cost of a single cap from 5 cents, to around 15-20 cents)
  • waxdart
    razor512the main difference with a silent PSU is the capacitor rating. Most noise ones use 1000 hour 105C capacitors, while a high end silent one will use caps that are in the range of 10,000 hour 105c, or even 125cmost of the voltage regulators are mostly the same though they may add a larger heatsink on them.you could pretty much turn a standard PSU into a silent one by swapping the caps and heatsinks. High quality capacitors are about 3-5 times more expensive (may take the cost of a single cap from 5 cents, to around 15-20 cents)


    Yeap, and you get a better, more reliable, energy efficient bit of kit too. Bit I don't think I'll be having a go a swapping them :)
  • freggo
    zeratul600Why does americans are so picky about the noise rate??? i never stop to think about that! it has never become an obstacle to enjoy my pc experience


    Not an 'American' thing, but a medical one. Noise pollution is becoming more and more of a problem; and affects long term hearing quality.
    No wonder people can no longer hear the difference between an MP3 and a CD recording.
  • willard
    Seasonic's X series units are pretty damn good. I've got the X650, and its fan doesn't even turn on until you apply a substantial load to the unit. Even then, it's still inaudible over the other noise in my case.

    Every now and then you can find it on sale for $120. A steal for the best 650W PSU in the world.
  • Anonymous
    I've been using a fanless psu in my HTPC for a few years now. A computer in the living room has different noise thresholds from a gaming PC.
  • vmem
    I ordered the seasonic just last night, needless to say, this article makes me feel very good about my purchase decision :)

    it'll be used in an HTPC/home media server. to those that have doubts about the usefulness of such a PSU, I will ask: "what's the point of having that nice audio system in your living room if all you're gonna hear is fan noise in the background?"
  • Anonymous
    I kinda wanted to see the KingWin 500W Stryker being compared to other fan-less units. Since it has 42 amps and it is platinum rated, it should be the best silent PSU in the market.
  • majorlag
    I am currently using the Seasonic x400 fanless in my silent fanless HTPC system. And a x560 in my desktop build. One of the best power supply brands I have ever used. Currently my pick for new systems being built.

    Another article is what got me hooked http://www.silentpcreview.com/Seasonic_X-400_Fanless_PSU, they basically had to resort to a hair dryer to make the thermal protection trip. A very good power supply that can put up with alot of heat before having to shut down.
  • nebun
    amuffinSeasonic, me gusta

    translate please...don't understand...thanks in advance