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

Which Fanless PSU Is Right For You?

Buy an actively-cooled power supply designed with low-noise in mind, or choose a fanless model. The choices are nearly the same, unless your hearing is acute. Of course, you could argue that if PSUs like the ones from Seasonic and SilverStone deliver high-quality DC power, just like the solutions with fans, why not go all-passive and cut the noise altogether?

Although it is true that the fanless power supplies from Seasonic and SilverStone are perfectly silent and ran in our test lab for extended periods of time, they did heat up about 50 degrees Fahrenheit above the ambient temperature. In an air-conditioned room, that shouldn't be a problem.

However, if you're in a room that gets beat-up by the sun all day or lacks A/C entirely, the thermal situation can get somewhat dicey, and a fanless power supply may very well hit its design limits. In that case, it's better to have a fan blowing through your power supply than to suffer the instability of an overheated component. It's worth noting that a PSU with a fan typically costs less than one without, due to the necessary measures to keep the passive unit cool enough.

But if you insist on absolute silence for your next build, Seasonic's X-460 rises to the top of our recommendation list. Its workmanship is excellent, and its price/performance ratio is quite good.

Manufacturerbe quiet!SeasonicSilverStone
Model Name and Numberbe quiet! Straight Power E9 CM 480 WX-460FLSST-ST50NF
Street PriceNot available in U.S.$130$200
Power Certification80 PLUS Gold80 PLUS Gold80 PLUS Bronze
Dimensions (WxDxH)150 x 180 x 86 mm150 x 160 x 86 mm150 x 160 x 86 mm
Weight2.6 kg2.77 kg3.5 kg
Operating Temperatureup to 40 °C0°C–50°C0°C–45°C
WarrantyFive YearsFive YearsThree Years
Power Specifications
SpecificationATX12V v2.31ATX12V v2.3ATX12V v2.3
Specified Output Power480 W460 W500 W
Max. Peak Output550 Wn/a550 W
AC Input100 - 240 V100 - 240 V110 - 240 V
AC Voltage SelectionAuto voltageAuto voltageAuto voltage
DC Output +3.3V24 A20 A18 A
DC Output +5V22 A20 A18 A
DC Output +12V (#1)18 A38 A38 A
DC Output +12V (#2)18 An/an/a
DC Output +12V (#3)18 An/an/a
DC Output +12V (#4)18 An/an/a
DC Output -12V0.3 A0.5 A0.5 A
DC Power +12V Combined456 W456 W456 W
Specified Hold-Up Time19 ms> 17 ms16 ms
MTBF300 000 hours> 100 000 hours50 000 hours
Cooling Specifications
Main Fan135 mmN/AN/A
Main Fan Speedup to 1200 RPMN/AN/A
Secondary FanN/AN/AN/A
Secondary Fan SpeedN/AN/AN/A
20+4 pin Motherboard1x (55 cm)1x (60 cm)1x (55 cm)
CPU1x (55 cm)1x (65 cm)1x 55 cm)
PCI Express 6-pin/6+2-pin (Graphics)0/2x (55 cm)0/2 (60 cm)1/1x (55-70 cm)
Molex 4-pin (Peripherals)4x (85–100 cm)5x (45-75 cm)6x (50–80 cm)
SATA Power8x (55–100 cm)5x (45-75 cm)6x (50–80 cm)
4-pin Floppy1x (115 cm)2x (90 cm)2x (95 cm)
Product Specifics
AccessoriesScrews, Velcro Strips, Cables TiesScrews, Velcro Strips, Cables TiesScrews, Velcro Strips, Cables Ties
Cable ManagementYesYes, Fully ModularNo