PHOTOS:  CPU's and Fans, Socket CPU diagonal edge

VIDEOS:  CPUs and their fans, Socket CPU diagonal edge, Socket CPU install, slot CPU install ATX

The speed of a CPU chip is measured in "Megahertz" (MHz).  The original IBM XT computer had a CPU that ran at 4.7 MHz.  Chips moved on from that original "8086" 4.7 MHz chip to the "286" (8-16 MHz), "386" (16-33 MHz), "486" (25-100 MHz), "Pentium" and "Socket 7" (60-233Mhz), Slot 1 "Pentium II" "Pentium III" and "Celeron" (233 MHz - 1700Mhz), Socket 370 "Pentium III", "Pentium 4" and "Celeron" chips (533-1800 MHz) (made by the manufacturer Intel), and Slot A and Socket A "Athlon" chips (made by the manufacturer AMD).

CPU's rated at over 1000 MHz are measured in "Gigahertz":  1000Mhz=1Ghz.  A 1.7 gigahertz CPU, for example, runs at 1700 MHz.  At the time of this writing, the fastest CPU's on the market are the 2 gigahertz Intel Pentium 4, and the 1.4 GHz AMD Athlon.  Megahertz ratings increase rapidly every year.  In 1995, for example, the fastest speed available was less than a tenth of the current quick processor (166Mhz), and that antique 4.7Mhz processor in the first IBM PC appeared only 20 years ago. 

To run most modern applications (Internet access, email, word processing, simple games and multimedia applications), a CPU speed of at least 233 MHz is expected.  If you plan on using your computer to work with large multimedia files (i.e., to edit sound and video), to play cutting edge 3D video games, or to manipulate/process large amounts of data, you should plan on using a machine with a faster CPU.

Other elements such as bus speed (the speed at which data is transferred across the motherboard), hard drive access time, RAM memory size and speed, video size and speed, and other component and software issues can dramatically affect the overall speed of a computer.  The heart of the computer's capabilities, however, along with its entire internal architecture, is built around the CPU.  When building or upgrading a system, deciding the type of CPU you will use - based on price and performance requirements - is the first step in choosing all of the other hardware that goes into the system.  You will have to purchase a motherboard which supports the speed and type of processor you use (i.e., socket or slot, Intel vs. AMD brands, etc…), as well as memory, video card, hard drive, etc., which match the performance of the CPU.  Keep in mind that it is very rarely cost effective to purchase the newest CPU on the market.  Prices for new technology drop so quickly that new CPU's often cost roughly half their initial price after about 6 months.  Buying technology that is several months old is typically the best choice for the majority of users.

Setting CPU jumpers on a motherboard:  Many modern motherboards can detect and automatically set up the CPU which is installed in it.  Just pop the chip in, and installation is complete.  Often, however, a MB may need to be configured in order to properly accept and run the CPU which is installed. There are three pieces of information a motherboard needs in order to use its CPU properly:  the "Bus frequency", the "frequency ratio", and the voltage of the chip.  This is most often set with "jumpers" - small pieces of metal and plastic which are placed on pin pads on the MB.  Setting up CPU jumpers on a motherboard is likely the most challenging part of building a computer from scratch or upgrading an existing machine.  Most motherboards come with a book containing explicit diagrams of jumper arrangements for every type of CPU that it can support, making CPU setup very easy.  Simply put jumpers on the mother board pins, as the book illustrates, for your chosen CPU, and setup is complete.

VIDEOS:  Jumpers on MB, MB - book CPU jumpers

PHOTO:  Clock ratio silk screened on MB

Some mother boards us a small switch pad called a "DIP switch" to make CPU settings:

PHOTO:  DIP switches

VIDEO:  DIP switches

The bus frequencies of modern CPUs are 66, 75, 83, 100, and 133 MHz.  The frequency ratio, or multiplier, is noted as some type of "X" value: 1.5x. 2.0x, 2.5x, 3.0x, … etc.

A 400Mhz CPU, for example, has a 100Mhz bus speed, and a 4x multiplier (100Mhz X 4 = 400 MHz).  A 333Mhz CPU has a 66Mhz bus speed and a 5.0x multiplier (the values are NOT always exact, especially on machines with odd MHz ratings (i.e., although 5 X 66Mhz actually equals 330Mhz, it IS the correct setting for a 333 MHz CPU)). 

The CPU voltage also needs to be set appropriately for the CPU - that information is typically printed right on the CPU itself and in the documentation provided with it by the manufacturer.  For example, you may see 2.4V on the CPU - just find the diagram for 2.4V on the motherboard, and put the jumper(s) where the diagram shows.  MB jumper layout information is typically silk-screened right on the motherboard, so that settings can be easily changed when no book is available.  Remember, on many new motherboards, this step is taken care of automatically by the motherboard.

Installing the CPU heat sink and fan:  Modern CPUs produce a great deal of heat, and require a heat sink and fan to cool the chip and avoid overheating and damage.  Below are videos demonstrating the attachment of a heat sink and fan to socket and slot type CPUs.

VIDEOS:   CPU fan install - socket, Heat Sink slot CPU, CPU fan install - socket #2, CPU fan - socket - another type of power connector