Hardware Reference
In-Depth Information
Thewattageratingcansometimesbemisleading.Notall500-wattsuppliesarecreatedthe
same. People familiar with high-end audio systems know that some watts are better than
others.Thisistrueforpowersupplies,too.Cheappowersuppliesmightinfactputoutthe
ratedpower,butatwhattemperature?Manycheappowersuppliesareratedatridiculously
low temperatures that will never be encountered in actual use. As the temperature goes
up,thepoweroutputcapabilitygoesdown,meaningthatinsomecasesthesesupplieswill
only be capable of 50% less than their rating under normal use.
Also, what about noise and distortion? Some of the supplies are under-engineered to just
barely meet their specifications, whereas others might greatly exceed their specifications.
Manyofthecheapersuppliesprovidenoisyorunstablepower,whichcancausenumerous
problems with the system. Another problem with under-engineered power supplies is that
theycanrunhotandforcethesystemtodosoaswell.Therepeatedheatingandcoolingof
solid-state components eventually causes a computer system to fail, and engineering prin-
ciples dictate that the hotter a PC's temperature, the shorter its life. Many people recom-
mend replacing the original supply in a system with a heavier-duty model, which solves
theproblem.Becausepowersuppliescomeincommonformfactors,findingaheavy-duty
replacement for most systems is easy, as is the installation process.
Inadequate Cooling
Somereplacementpowersupplieshavehigher-capacitycoolingfans,whichcanminimize
overheatingproblems—especiallyforhotter-runningprocessors.Ifsystemnoiseisaprob-
lem,modelswithspecialfanscanrunmorequietlythanthestandardmodels.Thesepower
suppliesoftenuselarger-diameterfansthatspinmoreslowly,sotheyrunmorequietlybut
move the same amount of air as the smaller fans. There are even fanless power supplies,
although these are more expensive and are generally available only in lower output rat-
ings.
Ventilation in a system is also important. In most prebuilt systems, this is not much of
a concern because most reputable manufacturers ensure that their systems have adequate
ventilation to avoid overheating. If you are building or upgrading a system your own sys-
tem, then the responsibility for proper cooling falls on you. In that situation it's critical
that your processor is cooled by an active heatsink and that the case include one or more
coolingfansforadditionalventilation.Ifyouhavefreeexpansionslots,Irecommendspa-
cing out any expansion cards in the system to permit airflow between them. Place the
hottest-running boards nearest the fan or the ventilation holes in the system. Make sure
that adequate airflow exists around the hard disk drives, especially for those that spin at
high rates of speed. Some hard disks can generate quite a bit of heat during operation. If
the hard disks overheat, data can be lost.
