Chapter2HardwarefromComputerInformationSystemsTextbook.pdf

Chapter 2

Hardware

2.1 The System Unit

2.2 Data and Program Representa-
tion

2.2.1 Digital data and numerical data

Most computers are digital computers which use a spe-
cific language to communicate within itself in to
process information. If there are programs running in
the background or a person is typing up a word docu-
ment for example, the computer needs to be able to in-
terpret the data that is being put into it by the human as
well as communicate to working components within it-
self. This language that digital computers use is called
binary code and is a very basic form of language com-
posed of only two figures; 1 and 0. Whereas the English
language is composed of 26 figures which we commonly
call the alphabet, computers use a language composed of
only two figures, hence its name Binary Code. Binary lit-
erally means two and refers to anything that consists of,
involves, or indicates two. The language known as Binary
Code operates on a system of 1’s and 0’s strung together.
Each 1 or 0 is referred to as a “bit.” “Bits” are the smallest
unit of data that a binary computer can recognize and ev-
ery action, memory, storage, or computation that is done
through a computer is composed of them. From playing
music through your speakers to cropping a photograph, to
typing up a document and preparing an important presen-
tation all the way down the line to browsing the internet
or picking up on a wifi signal in your area, everything
uses “bits” to complete the task needed. “Bits” string
into larger lines of information the way letters string into
words and then sentences. When eight “bits” are com-
pounded in this way they are then referred to as a “byte”.
“Bytes”, which are made up of “bits”, are commonly used
when referring to the size of the information being pro-
vided. For example, a song that is downloaded may con-
tain several kilobytes or perhaps even a few megabytes if
it is a whole c.d. and not just a single track. Likewise, pic-
tures and all other documents in general are stored on the
computer based on their size or amount of bytes they con-
tain. The amount of information that can be stored onto

a computer is also shown or displayed in bytes as is the
amount left on a computer after certain programs or doc-
uments have been stored. Since bytes can be extremely
long, we have come up with prefixes that signify how large
they are. These prefixes increase by three units of ten
so that a Kilobyte represents 1,000 bytes, a Megabyte
represents 1,000,000 bytes or one million bytes, a Giga-
byte represents 1,0000,000,000 or one billion bytes, etc.
Computers components have become so small that we can
now store larger and larger amounts of data bytes in the
same size computers resulting in the use of other larger
prefixes such as Tera, Peta, Exa, Zetta, and Yotta. Be-
low is a chart outlining the name of the prefix used and
powers of ten they symbolize.

0 1 1 0 1 0 0 0

1 1 0 1 0 0 0 0 0

1 0 0 1 1 1 0 1

0 1 0 0 1 1 1 00

1 0 0 1 1 1 0 0

1 1 0 0 1 1 1 0

b)

a)

c)

Bit shift

Digital Data Representation, otherwise known as how the
computer interprets data, is a key concept to understand-
ing computer data processing, as well as overall func-
tioning. Data is represented by particular coding sys-
tems. The computer recognizes coding systems- rather
than letters or phrases that the user of a computer views.
The actual process of the computer understanding cod-
ing systems is called digital data representation. A digital

23

24 CHAPTER 2. HARDWARE

computer operates by understanding two different states,
on or off. This means that the data is represented by
numbers- 0’s and 1’s, and is known as a binary computer.
The binary code is a very basic coding system for com-
puters to comprehend. An advantage to digital data com-
puting lies behind the binary coding systems. Although
the binary code has become decreasingly popular in the
professional, recreational fields due to an increase in tech-
nology, they still provide a use in programming. Digital
data creates a simple way to duplicate and transfer infor-
mation accurately from computer to computer, which is
why it is still used today.[1] The terminology for the small-
est unit of data is a bit, which consists of a single numeric
value,0 or 1. Bytes, on the other hand, consist of group-
ings of multiple groupings of bits. Bytes allow the com-
puter hardware to work more quickly and efficiently.[2]

(from the SI page on Wikipedia):
Representing data in a way that can be understood by a
digital computer is called Digital Representation and Bi-
nary Code is the most commonly used form of this. Bi-
nary Code is a Numerical Representation of data that uses
only 1 and 0 to represent every possible number. Mathe-
matics uses 10 symbols ranging from 1 TO 0 and include
2, 3, 4, 5, 6, 7, 8, and 9 as well. This Numerical Repre-
sentation of data is called the decimal numbering system
because it uses ten symbols. As shown on the chart, the
prefix deci symbolizes ten. In both systems, the position
of each digit determines to which power that number is
raised. In the deci-mal system each digit is raised by ten
so that the first column equals 1 (10^1) or ten raised to
the zero power, the second column equals 10 (10^2) or
ten raised to the first power, the third column equals 100
(10^3) or ten raised to the third power and so on. How-
ever, since Binary Code only operates with two symbols,
each digit is a power of two instead of ten. In binary
the first column equals 1 (2^0) or two raised to the zero
power, the second column equals 2 (2^1) or two raised
to the first power, the third column equals 4 (2^2) or two
raised to the second power, the fourth column equals 8
(2^3) or two raised to the third power, and so forth. Be-
cause the Binary system takes advantage of so few sym-
bols, the result is that more positions for digits are used to
express the same number than in decimal form, leaving
long lines of information for even the simplest expres-
sions.

2.2.2 Coding systems

There are a few different coding systems, EBCDIC,
ASCII and Unicode. EBCDIC (extended binary coded
decimal interchange code) was created for use in main-
frames, developed by IBM. The code uses a unique com-
bination of 0’s and 1’s, 8-bits in length, which allows for
256 different combinations. ASCII ( American standard
code for information interchange) was created for a more
personal use. ASCII uses a 7 bit code, though there is an
extended code which adds an extra bit, which nearly dou-

ASCII Code Chart-Quick ref card

A motherboard with an AMD chip.

bles the amount of unique characters the code can repre-
sent. however Unicode is a much longer string of code,
between 8 and 32 bits. With over one million different
possibilities, every language can be represented with this
code, every mathematical symbol can be represented, ev-
ery punctuation mark, and every symbol or sign from any
culture.

100 101 102 103 104 105 106 107 108 109 10A 10B 10C 10D 10E 10F

110 111 112 113 114 115 116 117 118 119 11A 11B 11C 11D 11E 11F

120 121 122 123 124 125 126 127 128 129 12A 12B 12C 12D 12E 12F

130 131 132 133 134 135 136 137 138 139 13A 13B 13C 13D 13E 13F

140 141 142 143 144 145 146 147 148 149 14A 14B 14C 14D 14E 14F

150 151 152 153 154 155 156 157 158 159 15A 15B 15C 15D 15E 15F

160 161 162 163 164 165 166 167 168 169 16A 16B 16C 16D 16E 16F

170 171 172 173 174 175 176 177 178 179 17A 17B 17C 17D 17E 17F

180 181 182 183 184 185 186 187 188 189 18A 18B 18C 18D 18E 18F

190 191 192 193 194 195 196 197 198 199 19A 19B 19C 19D 19E 19F

1A0 1A1 1A2 1A3 1A4 1A5 1A6 1A7 1A8 1A9 1AA 1AB 1AC 1AD 1AE 1AF

1B0 1B1 1B2 1B3 1B4 1B5 1B6 1B7 1B8 1B9 1BA 1BB 1BC 1BD 1BE 1BF

1C0 1C1 1C2 1C3 1C4 1C5 1C6 1C7 1C8 1C9 1CA 1CB 1CC 1CD 1CE 1CF

1D0 1D1 1D2 1D3 1D4 1D5 1D6 1D7 1D8 1D9 1DA 1DB 1DC 1DD 1DE 1DF

1E0 1E1 1E2 1E3 1E4 1E5 1E6 1E7 1E8 1E9 1EA 1EB 1EC 1ED 1EE 1EF

1F0 1F1 1F2 1F3 1F4 1F5 1F6 1F7 1F8 1F9 1FA 1FB 1FC 1FD 1FE 1FF

Non-Latin European scripts

African scripts

Middle Eastern and
Southwest Asian scripts

South and
Central Asian scripts

Southeast Asian scripts

East Asian scripts

American scripts

Cuneiform

Hieroglyphs

Notational systems

Symbols

Unallocated code points

As of Unicode 9.0

Roadmap to the Unicode SMP

Unicode is universal. With using 0’s and 1’s to represent
different data, it has become fit for any language used all
over the world. This code is replacing ASCII (American

https://en.wikipedia.org/wiki/SI

2.3. THE SYSTEM UNIT – THE MOTHERBOARD AND CPU 25

Standard Code for Information Interchange) because the
characters in this code can be transformed into Unicode,
a much more practical system for data. ASCII is known
as the alphabet code, and its numbering codes range from
0 all the way to 127 considered to be a 7 bit code. Alpha-
bets vary from language to langue, but 0’s and 1’s can
be understood worldwide. These codes apply to binary
coding systems, meaning the computer understands two
states of either On or Off. The problem with Unicode is
that it is not compatible with each computer system used
today. Windows 95/98 does not have the ability to run
Unicode while other Windows such as NT and 2000 are
closer to being able to. There is a program Sun Microsys-
tem’s Java Software Development Kit which allows you to
convert files in ASCII format into Unicode. While Uni-
code is a huge improvement for coding systems today, it
cannot process all symbols that are possible, leaving room
for new systems to one day take its place.[3]

2.2.3 Graphics Data

Image where individual pixels can be seen.

One type of multimedia data is graphics data. These data
are of still images, and can be stored in the form of a
bitmap image file. A bitmap image is a type of graphic
that contains pixels, or picture elements, that are arranged
in a grid-like pattern.[4] Each pixel is made up of a specific
group of numbers which corresponds to the color, and
the color’s intensity. Although there are a few other key
factors when determining the detail quality of an image,
pixels play an important role. An image with many pixels
allows there to be more potential of higher quality in that
image. However, this doesn’t mean that more pixels in
an image definitely results in a higher quality picture.[5]
When shopping for digital cameras consumers must be
aware of the amount of megapixels, or pixels by the mil-
lion, the cameras in front of them have. Today, an aver-
age person wishing to take decent and basic everyday pic-

tures will be satisfied with about an 8 megapixel camera.
In fact, many new smartphone cameras use 8 megapixels,
like the Apple iPhone 5C, a popular smartphone released
in September 2013. Someone with different intentions of
using images, perhaps for making high definition prints,
will require a camera with more megapixels. This would
allow for their prints to be large, but with appropriate and
exceptional quality.[6]

2.2.4 Audio Data

Audio Data is very similar to graphics data in that it is
understood in pieces. Instead of using pixels, however,
audio data uses samples. Audio data is usually recorded
with an input device such as a microphone or a MIDI con-
troller. Samples are then taken from the recording thou-
sands of times every second and when they are played
back in the same , they create the original audio file.
Because there are so many samples within each sound file,
files are often compressed into formats such as MP3 or
MP4 so that they take up less storage space. This makes
them easier to download, send over the internet, or even
store on your MP3 player.

2.2.5 Video Data

Video data is also similar to graphic and audio data, but
instead of using pixels or samples, video data is recorded
with the use of frames. Frames are still images that are
taken numerous times per second and that when played
simultaneously, create a video (most films are recorded
using twenty-four frames per second).[7] Similar to audio
data, because video data contains so much information,
the files can be compressed, making it possible for full
length movies containing thousands of frames to be stored
on optical discs.

2.3 The System Unit – The Mother-
board and CPU

Motherboard

“The motherboard can be thought of as the “back
bone” of the computer.” This quote is from the article
Motherboard. Inside the system unit contains the moth-
erboard. The motherboard is the “glue” of the computer.
It connects the CPU, memory, hard drive, optical drives,
video card, and sound card together. The front of the
motherboard are peripheral card slots. The slots contain
different types of cards which are connected to the moth-
erboard. The left side of the motherboard contain ports.
The ports connect to the monitor, printer, keyboard,
mouse, speakers, phone line, and network cables.[8]

Like many of the components of computers, mother-

http://pcsupport.about.com/od/componentprofiles/p/p_mobo.htm

26 CHAPTER 2. HARDWARE

Realtimeclock Motherboard Baby AT crop

boards have not always been as advanced as they are to-
day. Motherboards on early PCs did not have many inte-
grated parts located directly on the board. Instead, most
of the devices, such as display adapters and hard disk
controllers, were connected through expansion slots. As
technology advanced, more and more devices were built
in directly to the board itself. At first, this began to cre-
ate problems as manufacturers began to find that if one of
the devices on the motherboard was faulty or in some way
damaged, that the entire motherboard must be replaced.
This led manufactures to change the design in a way that
allowed them to remove faulty parts easily and replace
them, especially parts that are growing and changing so
quickly, such as the RAM or CPU. Today, a motherboard
comes equipped with many parts working in conjunction
with each other. One can find anything, from back up bat-
teries, keyboard and mouse connectors, to cache memory
chips, in close proximity to the CPU. The computer is
able to do tasks faster as its components continue to be
closer to one another. The advancement of technology
has allowed for these parts to become smaller and more
powerful, allowing more surface area on the motherboard
to fit more devices. It is common today to find even audio
and video components built into it as well. With technol-
ogy moving as fast as it is, one may wonder what a moth-
erboard will be capable of containing in the near future.[9]

• Annotated Motherboard

• Motherboard Diagram

CPU

The CPU is the abbreviation for the central processing
unit. The computer needs the CPU in to function
correctly. It is known as the brains of the computer where
the calculations occur. The microprocessor and the pro-
cessor are two other names for the central processing unit.
The Central processing unit attaches to a CPU socket on
the motherboard. A common CPU is called the multi-
core CPU. This specific type of CPU is efficient because

Motherboard

it allows computers to work on more than one task at a
time. Also, these multi core CPU’s experience less over
heating than the original CPU which causes much less
problems to the computer. A typical CPU is two by two
inches.

• Intel i7 940

• AMD Dual Core

History of the CPU

The Intel 4004

2.4. THE SYSTEM UNIT – MEMORY, BUSES, PORTS 27

The first CPU ever made was the Intel 4004, which was
designed by Federico Faggin. After ten months of Faggin
and his colleagues working on the chip, it was released
by Intel Corporation in January 1971. Even though this
first generation, 4-bit microprocessor could only add and
subtract, it was a major breakthrough in technology. The
amazing quality was that all of the processing was done
on one chip, as opposed to prior computers which had a
collection of chips wired together. This invention lead to
the first portable electronic calculator.[10]

While technology has advanced quite a bit since 1971, old
technology is not as “out-of-date” as one thinks. There
are still CPU chips made in the 1970’s and 1980’s that are
still being used today. Personal computers, such as PC’s
and Mac’s, use faster, more up-to-date CPU’s because the
users run many programs at the same time. However, the
more simple computers embedded in cars, printers, and
microwaves can still use the older forms of microproces-
sors. For example, one famous CPU was the MOS 6502,
made in 1975, and it was still being used in many ap-
pliances up until 2009. Control processing units are the
key component in any computer, and thus sometimes the
simpler styles work best.[11]

2.4 The System Unit – Memory,
Buses, Ports

2.4.1 Memory

The Template:Gaps byte (512×220) capacity of these RAM mod-
ules is stated as “512 MB” on the label.

Memory identifies data storage that comes in the form of
chips and is used to store data and programs on a tem-
porary or permanent basis. There are two main types
of memory storage which are random- access memory
(RAM) and read-only memory (ROM). Inside the sys-
tem unit, ROM is attached to the motherboard. Random-
access memory can read data from RAM and write data
into RAM in the same amount of time. RAM is measured
in bytes and includes the cache memory and registers. It

is volatile which means that it loses the information/data
stored on it when the power is turned off. In to re-
trieve an important file at a later date, one needs to store
it on a separate, non-volatile, storage medium (such as a
flash drive or hard-drive) so that, even though the infor-
mation is erased from RAM, it is stored elsewhere. RAM
has different slots where it stores data and keeps track of
addresses. Read-only memory cannot be written to and is
non-volatile which means it keeps its contents regardless
of whether the power is turned off or not. Flash memory
(solid-state) is starting to replace ROM. It is also a non-
volatile memory chip that is used for storage on devices,
like mobile phones, tablets, digital cameras, etc. This
type of memory can often be found in the form of flash
drives, SD cards, and Solid-State hard drives. The reason
for this is so that the data can be quickly updated over
time while taking up a smaller amount of physical space
in comparison to its precursors. Flash memory is also
more resistant to outside forces, such as electro-magnetic
fields or shock, than other memory alternatives such as
traditional hard-drives.

A microprocessor, which may use cache memory.

Cache memory is a specific kind of memory that al-
lows a computer to perform certain tasks much more
quickly. A good analogy from HowStuffWorks compares
the computer to a librarian, data to books, and cache to a
backpack.[12] Suppose somebody walks into a library and
asks the librarian for a copy of the book Moby Dick. The
librarian goes back into the room full of books, grabs that
book, and gives it to the reader. Later that day, the reader
returns, having finished the book, and gives it back to the
librarian, who returns it to the same storage room. Then,
a second reader walks in asking for the same book, Moby
Dick. The librarian has to get up and go all the way back
to the room in to get the book he was just handling,
which is a waste of time. Instead, suppose the librarian
had a backpack that could store up to 10 books. When
the first person returns Moby Dick, the librarian puts it
into his backpack instead (after making sure the back-

https://en.wikibooks.org/wiki/Template:Gaps

28 CHAPTER 2. HARDWARE

pack doesn’t have 10 books in it already.) Then, when
the second person comes in requesting that same book,
the librarian can just check his bag, get the book out, and
hand it to the second person without having to walk all
the way back into the other room.
Cache memory functions like that backpack. It stores
previously accessed data in a specific area with a limited
amount of memory so that the processor can get this data
much more quickly.

2.4.2 Ports

Parallel Printer Port

Ports are on the outside of the system unit and they are
used to connect hardware devices. There are physical
ports and virtual ports. A physical port is a physical con-
nection to a computer where data is transferred. It is
when something is physically plugged into the computer
or some other device. Virtual ports allow software ap-
plications to share hardware resources without having to
physical connect to each other or to interfere with one
another.[13] Parallel ports are most often used with a key-
board, printer or mouse, but these are more commonly
known as legacy ports instead. Each port has a certain
connector to plug it into the computer. Different type
of ports would be power connectors, VGA monitor port,
USB ports, Firewire port, HDMI port, Network port, au-
dio ports, and empty slots. The connectors would be
Monitor (VGA, HDMI), USB, Firewire, network, and au-
dio connector. Each port has also a different purpose and
connector. Almost all PCs come with a serial RS-232C
port or a RS-4222 port and they are used for connect-
ing a modem, mouse, or keyboard. They also have par-
allel ports that are used to connect printers. These are
also considered USB ports because they are physical ports
and which standardize communications between comput-
ers and peripheral. USB ports were created in the mid
1990’s; USB stands for Universal Serial Bus. There are
also network ports used to connect a computer to a net-
work. Ethernet was developed in the 1980s and it is a
system for connecting a number of computer systems to
form a local area network.

A serial port is used to connect modems to personal com-
puters. The term “serial” signifies that data sent in one
direction always travels over a single wire within the ca-
ble. The last main kind of port is the FireWire, which are
used to connect FireWire devices to the computer via a
FireWire connector. These are used with mostly digital
video cameras and other multimedia devices.

2.4.3 Thunderbolt port

Thunderbolt-Connector

A Thunderbolt port connect peripheral devices through
that cable. These ports allow for you to connect more de-
vices to your computer and is very fast. Thunderbolt ports
use hardware controllers I/0 protocols onto one efficient
protocol with the use of just one cable. I/O technology
is input and output is a device that that transfers the data
to the computer peripherally (a CD-ROM would be an
example of an I/O technology).This port lets there to be
full bandwidth for both directions of the port, thus allow-
ing the user to faster and more efficient with the ports it
has to connect. This type of technology allows for people
to plug in as many devices they could use on their com-
puter and not slowing any of those devices down. The
thunderbolt port is also small so it is easy to travel with as
well.[14]

2.4.4 Power supply unit

Computers need power. There are two main functions
the PCUs are responsible of. The first is to convert the
type of electrical power available at the wall outlet such
as110V 60Hz AC (alternating current) or 230v 50Hz AC
to the type the computer circuits can use. The other cru-
cial task is to deliver low voltages to each device due
their requirements. The converting currents could be
represented either by built in PSU (desktops, servers,
mainframes) or by the separate power supply adapters
for computers with rechargeable batteries inside (laptops,
tablets). Three main voltages are used to power com-
puter : +3.3v, +5v, and +12v DC, Usually, the +3.3 or

2.5. HOW THE CPU WORKS 29

PSU-gold-rear

+5 voltages are being used by logic circuits and some dig-
ital electronic components (motherboard, adapter cards,
and disk drive logic boards) while the motors (disk drive
motors and any fans) use the +12v power. The power sup-
ply must provide a good, steady supply of DC power for
the proper system operation. Devices that run on voltages
other than these must be powered by onboard voltage reg-
ulators. For example the CPUs operate 1.5V and 2V and
require very stable power with high power consumption.
[15]

2.4.5 Ethernet Cable in Theatre

A commonly used cable today is Ethernet cable. You a
probably most familiar with its use involving the internet
in your home, mostly going from your modem, to another
computer of to a Wi-Fi router. However, the use of Eth-
ernet cable has been instrumental in the changing would
of technical theatre. Before its introduction, the most
common computer cables used in theatre were DMX and
XLR, for lighting and sound respectively. This issue with
this is that each cable can only carry the information for
one device, be that a microphone or light. In addition, if
these cables are stored improperly, they can corrupt the
information being transmitted. Ethernet is much smaller,
and can transmit far more data. Also, there is less of a
danger regarding storing cable. Ethernet, combined with
new operating system and equipment, has made thing far
more efficient. For example, an analog board must have
one XLR cable go to each microphone, so if you wanted
to run 40 microphones, you must have 40 channels avail-
able on your soundboard. Also, the size of a cable with
40 smaller lines inside it can reach a one-inch diameter,
and can weigh several hundred pounds. Now, a digital
soundboard can control up to 100 microphones on a sin-
gle Ethernet cable.

An Ethernet cable

This is a Yamaha digital soundboard capable of running ethernet

2.5 How the CPU Works

CPU Architecture and Components

As previously discussed on this page, the CPU is a com-
plex piece of the computer made up of many parts. The
way these parts all fit together inside the CPU is differ-
ent in each processor but they mainly contain the same
parts from device to device. The most abundant part in
the CPU would be the transistor. Modern CPU’s typi-
cally hold several hundred million transistors with some
of the more high-end computers holding over a billion,
and for good reason. Calculations in a computer can be
performed thanks to the combination of transistors turn-
ing off or on. Besides these transistors, there are sev-

30 CHAPTER 2. HARDWARE

A CPU core

eral parts that make up the CPU. Some of these include
the arithmetic/logic unit (ALU) and floating point unit
(FPU), the control unit, and the prefetch unit. The ALU
is the part of the CPU that deals with the mathematics in-
volving whole numbers and any functions done with those
numbers. The FPU takes care of the mathematics with
other numbers like fractions, or numbers with decimal
places.[16] These two parts work hand in hand, using arith-
metic and logical processes, to allow you to perform ba-
sically any function you perform on your computer. The
control unit takes charge in controlling where and when
information is transferred to and from the CPU. When in-
formation leaves the control unit, it is usually sent to the
ALU/FPU where it can be converted into a process. The
prefetch unit, as its name implies, fetches data before it
is needed. It uses a sequence of processes to guess what
information will be needed next, and have it readily avail-
able before the time it needed. Other components of the
CPU include the cache, the decode unit, and the bus in-
terface unit. The cache serves as high-speed memory for
instructions that the CPU would like to access faster, in
other words instructions that the CPU would rather avoid

retrieving from RAM or the hard drive. The decode unit,
just as it sounds, decodes instructions. Once the prefetch
unit fetches data, the data goes through the decode unit
so the instructions can be understood by the control unit.
The bus interface unit allows communication between the
the core and other CPU components. Think of it as liter-
ally a bus, taking information from one place and trans-
porting it somewhere else. [17]

2.6 How the CPU Works

The Internal Clock

Every computer actually has two different clocks. One
is the virtual or system clock that runs and is displayed
whenever the computer is on and running.[18] The other
is a real-time clock or hardware clock that runs continu-
ously, and is responsible for tracking the correct time and
day. This device does not count time in days and hours
for example. Instead it just runs a counter at times per
second. As far as the century goes, it is the job of the
BIOS, the Basic Input-Output System, to track this and
save it in the non-volatile memory of the hardware clock.
These two clocks run independently on each other. The
system clock is physically a small quartz crystal that can
be found on the motherboard. It also helps synchronize
all computer functions by sending out signals- or cycles-
on a regular basis to all parts, much like a person’s heart-
beat. Hertz is the unit of measure used to count the num-
ber of cycles per second. For example, one megahertz is
one million ticks of the system clock. This clock is very
important to the CPU because the higher the CPU clock
speed, the more instructions per second it could process.
Since the entire system is tied to the speed of the system
clock, increasing the system clock speed is usually more
important than increasing the processor speed.
PCs in the past only had one unified system clock with
a single clock, which drove the processor, memory, and
input/output bus. However, as technology advanced, the
need for a higher speed, and thus multiple clocks, arose.
Therefore, a typical modern PC now has multiple clocks,
all running at different speeds to enable any data to
“travel” around the PC. Furthermore, two CPUs with the
same clock speed will not necessarily …