Computer System Components
We describe the computer system components that
make it tick and what counts in those components
A computer is like a brain which can think,
calculate, retrieve and organize information for its human master. This
brain is supplied with parts that provide allow for input to it and
allow it produce output for presentation to the one using it.
Central Processing Unit
The thinking part of the brain
of the computer is the CPU or Central Processing Unit.
This component provides all the control and manages calculations and
manipulation of data.
Computer manufacturers are always trying to
squeeze more speed and multiprocessing capability (doing multiple
things at the same time) out of it. This has led to the dual core or
multiple core CPU which is popular today. A core is basically a
computer so that a dual core computer is really 2 computers in one.
Computer speed is usually measured in GHz which
means Gigahertz which in turn mean billions of cycles per second. The
basic idea is that the higher the number of cycles, the faster the
computer is. Today the computer manufacturers are depending on the
combined power of multiple cores to provide the power instead of the
number of GHz.
The CPU has no memory. It is like a genius with
Alzheimer's. In order for the CPU to access and manipulate data, RAM or
random access memory is needed to hold the information that the CPU is
working on. The amount of memory that a computer has is probably the
most important factor affecting the computer's speed. This is discussed
in detail in my article What
everyone needs to know in order to do an effective computer speed up.
Modern computer memory sizes are measured in
Gigabytes or billions of bytes. Modern PC operating systems need at
least 1 gig to perform smoothly.
The buzzwords that are usually associated with
- dual channel - 2 streams of data can be moving
between the memory and the computer at the same time
- ddr, ddr2, ddr3 - double data rate versions 1,
2, 3 etc. which are methods of squeezing more speed out of the memory
at each step
- sdram - synchronous dynamic random access
memory which is a type of solid state computer memory than has an
ordered method of transferring the information that makes it work faster
- xxx MHz - speed of the memory in MegaHertz. The
higher the better.
The bottom line of all these technologies is that
they speed up the memory in one way or another.
Memory is supplied in the form of DIMMS dual
in-line memory modules. These are elongated chips that supply blocks of
memory in multiples of 256 megabytes.
DIMM graphic courtesy of Wikipedia.com
important is the number of DIMM slots that your computer's motherboard
has. It generally has 2 or 4. Therefore, assuming a 1 gigabyte DIMM, 2
slots would supply 2 gigs and 4 slots would supply 4 gigs.
The the RAM memory is like the current thoughts or
short term memory of a person, the disk drive is the long term memory.
It holds a vast amount of data, programs and control software to
support computer system and user activity. Current computer storage
technology has advanced to the stage that a 100 Gigabyte drive is quite
inexpensive. Getting anything less would needlessly limit your ability
to store and save information.
Disk memory is much slower than RAM memory but it
is much cheaper so that it is used to backup and supplement memory
The operating system is the software that contains
the logic to control all the computer hardware, software and systems.
It provides the capability to interact with the computer and provides
access to and control of all the programs. It also defines and
maintains a scheme whereby data can by filed on the computer and
retrieved when necessary. The most popular operating systems on the PC
are Windows XP and Vista with Linux and other variants controlling a
mintority of computers. The MAC currently uses OS x which is a variant
of the Unix operating system.
Speed of Thought
The impact of the various components of the
computer brain and their impact on speed is discussed in What
everyone needs to know in order to do an effective computer speed up.
Input and Output
The keyboard is the most direct form of human
input to the computer. It can be used to generate data and documents,
provide information for commands or to initiate operations on the
The standard keyboard has the typical typewriter
QWERTY layout of the letters. There are variations with different
Things to consider in a keyboard are wireless or
wired, letter layout, additional features such as special keys, numeric
keypad and mousepad.
The mouse is a device which allows for easy
navigation and manipulation of the computer screen in a graphical way.
The forward and backward motions of the mouse are translated into up
and down motions on the screen or active window. Right or left motions
are translated into right and left motion on the display.
The mouse also has buttons which can be used to
select items and initiate programs represente by icons (little pictures
that represent programs or functions) or to drop down a context
Choices of mice included wired or wireless,
optical or rubber ball based (optical is MUCH better so the rubber ball
should be avoided), 1 button up to 3 button mice, different shapes to
better fit one's hands and righty and lefty versions.
Modern digital devices such as digital cameras,
PDAs, handheld and Mobile computers, telephones, and music players use
different types of memory cards to support their operations. Often it
is desirable to transfer images, music or data to and from these
devices to the computer.
A media reader provides this capability.
The media readers are usually described as 10 to
1, 13 to 1 or 15 to 1 etc. to indicate the number of different types of
memory cards supported.
A monitor is a television like electronic device
that displays images on its screen that correspond to the computer
activity currently occurring.
Issues to consider in a monitor are screen size
generally ranging from 15 inches to 27 inches measured diagonally, CRT
(almost obsolete) or flat screen, resolution, inputs (this determines
what you can connect to it and whether it can serve as your TV screen),
analog or digital and widescreen (wider for the same screen height) or
The graphics/video card of a computer converts the
electronic signals that the computer generates or transfers to it from
external input into visual images. The level of clarity, definition and
detail of the images depends on the power of the video card being used.
This item is discussed in detail in my article Video
Sound is supported on the PC by electronics that
convert digital data into analog sound. It may be built into the
motherboard of the computer or it may be provided by an expansion card
that is inserted into a slot on the motherboard. Integrated sound is
fine for most uses but if you want a rich surround sound type of sound
or rich gaming sounds expansion cards can provide this capability.
Computer speakers project the sound generated by
the computer to the listener. They range from basic to surround sound
and subwoofer units that enhance the bass of the generated sound. One
space saving form of speaker is a unit that connects to the bottom of
DVD and CD
DVD and CD readers and burners allow for getting
input from DVDs and CDS and for creating them. Most software is
provided on CDs or DVDs.
Burning software allows users to create backups,
transfer files and generate audio or video discs that can be played
back on standard players.
This item is discussed in detail in Deciphering
DVD and CD.
Modems (modulator-demodulator) is a device that
converts the ones and zeroes of a computer into a signal that can be
transmitted and vice versa. Phone based modems allow users to use their
phone lines to communicate with networks, notably the internet and also
allows faxes to be received and sent on the computer. Cable or DSL
modems convert internet signals to computer data and vice versa to
allow for internet and general network communication.
A network is generally an interconnection of a
group of computers. The Internet is nothing more than a huge
interconnection of computers.
Obviously, networks allow for transfers back and
forth of all sorts of information and media between the computers. This
item will be discussed in detail in a different section of this site.
Computer printers generate hard copy output. The
output can be documents or graphics.
Some of the main choices in printers are type of
printer such as laser or inkjet, black and white or color, output speed
and the cost of supplies such as toners or ink cartridges.
from Common Computer System Components to Ask the Computer Doc home.