Silent PC Power Supplies


Noise has been a growing issue for desktop computers for some time now. The primary source of noise within computer systems is fans used to cool down the internal components. FX700-GLN  typically have had one or two fans inside of them to cool down the internal components used to convert the voltage from the wall outlet to the lower voltage power for the electronics. The problem now is that personal computers are being placed in environments such as the home theater that are meant to be quiet. Because of this, more and more power supplies are now being labeled as silent.

The Sound of Silence

One of the first things consumers should be aware of is that a part being marketed as silent may still produce noise. All sound levels are recorded in decibels (dBA). The higher the decibels, the louder the noise. The human ear has a difficult time noticing certain sound frequencies and very low decibels. Because of this, many manufacturers will label devices as silent even though they do generate noise. The typical definition of silent by a manufacturer can be anything from around 20dBA to 30dBA. For the sake of comparison , whispering is roughly 20dBA while 60dBA is typical of a normal conversation.

The reason that the companies are able to market these low noise  FX700-GLN   as silent is that these decibel levels are very difficult to detect over the noise of other components inside of the computer such as the CPU cooling fan, hard drives and even the CD or DVD drive. It is important to check the specifications of a power supply to see what the actual decibel rating of any fans that might be in the power supply for how much noise it might actually produce.

With the increase in items such as temperature controlled fans, improved fan bearings and larger fans, many of the power supplies on the market produce very little noise. Most units that produce less than 25dBA in noise are still quite acceptable for computers in low noise environments such as a home theater PC.

Fanless Power Supplies

The most recent push for silent computing is the development of the fanless power supply. These units opt to use passive cooling instead of fans to move air through the unit. The construction of fanless units will vary depending upon the manufacturer. Most of them employ aluminum instead of steel for the basic case because of its better heat dissipation. This is about all they may share in common. Some designs have holes drilled throughout the case to increase airflow, others have large fins on the exterior to increase the surface area and then others have heatsinks that protrude out the back of the unit.

The obvious advantage to a fanless design is the lack of any fan noise, but there are some drawbacks to such units. Typically a fanless power supply has a much lower wattage rating over more traditional designs. This is due to the increased levels of heat produces as the wattage of the unit increases. Previous units were found in the 350 to 400W range, but now some are available up to 500W and up. Regardless, its best not to use fanless units for demanding computers such as a running top of the line or dual graphics cards.

The larger issue though is the life of the FX700-GLN  . Heat has a detrimental affect on the life of components, which is why active cooling is prevalent in computer systems. Because there are no fans moving air through the fanless designs, they tend to get much hotter than traditional units. This tends to result in shorter lifespans for fanless designs. When looking at buying a fanless design, check the MTBF of the unit as well as the temperature it is rated at. For example, 80,000 hours is pretty good, but it is much better if it is rated with that life at 50C than at 25C.

If you are going to look at using a fanless power supply, be sure to check the size and design of the unit. The designs used in some of the fanless units can prevent them from being used with some desktop PC cases. This is generally an issues for any power supply that tends to use heatsink fins that protrude from the read of the unit and outside of the case.


There has been a lot of development in terms of reducing noise within computer power supplies and this has been heavily driven by the movement towards multimedia computers in places such as a home theater. If you want to have a low noise computer, shopping for a power supply has a large number of options. Hopefully this articles has shed some light on what the industry deems as silent and what types of units you might want to consider when putting together a low noise system.

FSP FX700-GLN Power Supply

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