Learn about the technologies behind the Internet with The TCP/IP Guide!
NOTE: Using robot software to mass-download the site degrades the server and is prohibited. See here for more.
Find The PC Guide helpful? Please consider a donation to The PC Guide Tip Jar. Visa/MC/Paypal accepted.
View over 750 of my fine art photos any time for free at DesktopScenes.com!

[ The PC Guide | Systems and Components Reference Guide | Power ]

The Power Supply

The internal power supply is responsible for converting your standard household power into a form that your computer can use. The power supply is responsible for powering every device in your computer; if it has a problem or is of low quality you may experience many difficulties that you may not realize are actually the fault of the electrical system. This section discusses what makes up the power supply and how it works in detail.

The power supply plays an important role in the following areas of your system:

  • Stability: A high quality power supply with sufficient capacity to meet the demands of your computer will provide years of stable power for your PC. A poor quality or overloaded power supply will cause all sorts of glitches that are particularly insidious, because the problems occur in other, seemingly unrelated, parts of the system. For example, power supplies can cause system crashes, can make hard disks develop bad sectors, or cause software bugs to appear, problems which can be very difficult to trace back to the power supply.
  • Cooling: The power supply contains the main fan that controls the flow of air through the PC case. This fan is obviously a major component in your PC's cooling system.
  • Energy Efficiency: Newer PC power supplies work with your computer's components and software to reduce the amount of power they consume when idle. This can lead to significant savings over older systems.
  • Expandability: The capacity of your power supply is one factor that will determine your ability to add new drives to your system, or upgrade to a more powerful motherboard or processor. Many people don't realize, for example, that a high-speed Athlon CPU and motherboard consume far more power than a similar Pentium-based system, and the power supply needs to be able to provide this power. If you build a new system with a power supply that barely meets your needs, you may have to replace it when you upgrade down the road.


These pie charts show vividly why you should pay attention to your power. Despite
their low cost compared to other PC components, power and cooling are responsible
for a large percentage of overall system problems. Despite this, many people  who
would pay $200 to get a CPU 10% faster than another one--even though it will make
almost no noticeable difference in performance and will be obsolete in months--won't
pay half that for a quality power supply that will last for years and years.
(Source: Strategic Research Corporation, via PC Power & Cooling, Inc.)

Images PC Power & Cooling, Inc.
Images used with permission.

Despite its critical role, the power supply is one of the most ignored and under-studied components in the PC. In fact, some people don't even bother to check out what power supply is included when they purchase a case! Upon these faulty foundations, important PC systems are built. Don't let that happen to you. This section of The PC Guide will help you to understand the power supply and what to look for.

Next: Power Supply Functions and Signals

Home  -  Search  -  Topics  -  Up

The PC Guide (http://www.PCGuide.com)
Site Version: 2.2.0 - Version Date: April 17, 2001
Copyright 1997-2004 Charles M. Kozierok. All Rights Reserved.

Not responsible for any loss resulting from the use of this site.
Please read the Site Guide before using this material.
Custom Search