Hardware Reference
In-Depth Information
power supply can support them. Be sure you have enough power to run all your expan-
sion cards, especially video cards. However, remember that most cards draw less than the
maximum allowed. Today's newest processors can have high current requirements for the
+5V or +3.3V supplies. When you're selecting a power supply for your system, it pays to
beconservative,sobesuretotakeintoaccountfutureupgradesoradditionstothesystem.
Manypeoplewaituntilanexistingcomponentfailstoreplaceitwithanupgradedversion.
If you are on a tight budget, this “if it ain't broke, don't fix it” attitude might be neces-
sary. Power supplies, however, often do not fail completely all at once; they can fail in an
intermittent fashion or allow fluctuating power levels to reach the system, which results
in unstable operation. You might be blaming system lockups on software bugs when the
culpritisanoverloadedpowersupply.Inaddition,aninadequateorfailingsupplycausing
lockupscanresultinfilesystemcorruption,whichcausesevenfurthersysteminstabilities
(which could remain even after you replace the power supply). If you use bus-powered
USBdevices,afailingpowersupplycanalsocausethesedevicestofailormalfunction.If
youhavebeenrunningyouroriginalpowersupplyforalongtimeandhaveupgradedyour
system in other ways, you should expect some problems, and you might want to consider
reloading the OS and applications from scratch.
Although there is certainly an appropriate place for the exacting power-consumption cal-
culations you've read about in this section, a great many experienced PC users prefer the
“don't worry about it” power calculation method. This technique consists of buying or
building a system with a good-quality 500-watt or higher power supply (or upgrading to
such a supply in an existing system) and then upgrading the system freely, without con-
cern for power consumption.
Power Savings
Over the past few years, energy conservation has become a major focus for appliances,
electronics,andespeciallyforcomputers.Savingpowercanbeaccomplishedthroughsev-
eralmeans.Oneistousemoreefficientcomponentsthatsimplyuse(orwaste)lessenergy
to do the job. The other is to properly manage the computer hardware so that components
that are not being used are powered down or put into standby modes. By using more ef-
ficient components and turning off specific components of the PC when they are not in
use, you can reduce the electric bill and avoid having to power the computer up and down
manually.Thisnotonlysavesenergy,butitmakesthesystemmoreconvenienttouse.The
following sections discuss both of these approaches to saving power.
