BTEC National
Diplomas in
Information Technology
Assignments submitted should include this front cover sheet and a bibliography or description of where
information has been obtained.
Work should be spell checked and presented in order as laid out by the assignment.
Unit Number
Unit Title
Assignment Number
Student Name
Tutor
2
Computer systems
1
Damian Korcz
Keith Turner
Declaration
The assignment that I am presenting is completely my own work. Any text, images or other material
used in this assignment that has been obtained from the Internet or any other source used has been
appropriately referenced and if appropriate permission gained to be used.
I acknowledge that any work presented as my own but is copied (plagiarised) either by word-for-word
or by general presentation of ideas may lead to disciplinary procedures.
Unit 2 Computer Systems
Motherboard Form Factors
Motherboards come in various sizes also known as Form factors. The most popular form
factors that we can find in the modern computers are Extended ATX (305 x 330mm),
Standard ATX (305 x 244mm), Micro ATX (244 x 244mm) and Mini ITX (150 x 150mm).
The reason why there are so many different form factors is because they are used in
different sizes of computers or more specifically different size of cases.
(Source of the image: LINK)
Processor Types and Manufactures
Processors come in different sizes depending on the type of the motherboard they can
fit. Currently 2 leading companies; AMD and Intel are dominating the Computer
processor market. Processors come with different amounts of cores meaning that
depending on how many cores and at which speeds they work will depend on how fast
they can compute a given task. Modern processors have more than one core, usually 2,
4, 6 or even 8. Processor sizes may vary depending on which company produces them or
on the size of the motherboard. There also other companies that produce processors for
mobile devices such as smartphones or tablets. Examples of companies that specialise in
mobile processors are: Qualcomm with their Snapdragon processors or NVidia with their
Tegra Processors.
Fans, Heatsinks and Power Supplies
In a system it is essential to keep all of your components cool when they are on load and
working hard. Usually you can find fans round the actual case to draw in fresh air into
the case to cool the components, to dissipate the heat and take it out with the exhaust
fans. Fans come in different sizes depending on the size of the case and the usage of the
fan.
Heatsinks can usually be found on the processor, RAM and other components found on
the motherboard or expansion cards. Their main purpose is to be connected to the
component with thermal paste to help it get rid of the heat and sometimes heatsinks
have a fan stuck to it to speed up the process and keep the component cool.
Power supplies much like cases and motherboards come in different form factors. There
are also various types of power supplies such as a non-modular, semi-modular and
modular meaning that the modular one has all of the cables coming out of it and you
can’t take them out. A semi-modular one has some of the cables permanently coming
out of the power supplies and some cables for you to install in if you need them. Finally
there are the modular power supplies with allow you to only plug in the cables that you
will need and keep the rest unplugged. This is a way to keep you case tidy and reduce
the amount of useless cables lying around. Power supplies also have a rating called 80
plus with references to the efficiency, meaning that out of 100% of power 80+ at full
load will be used to provide power and the remaining will be waste energy such as noise
or heat.
Motherboards
Motherboards in a computer are like the body for your organs; it keeps everything
connected together and works like a motorway which components use to communicate
with each other. Motherboard is a large PCB (Printed Circuit Board) that is found in
various devices such as desktop computers, laptops, mobile phones, etc. Motherboards
hold all of the components such as the processor, RAM, graphics card, hard drives and
other components.
North and South Bridges
North and south bridges are two chips on the motherboard which are inside the core
logic chipset. Those bridges are used to manage all of the data that is being transferred
throughout the motherboard and helps them to communicate.
The reason why we have separate chips such as the south and the north bridge is
because it is quite difficult to integrate together.
The north bridge is in charge of transferring all of the data that has been calculated by
the computer processing unit (CPU), the random access memory (RAM) and the
accelerated graphics port (AGP). In the modern systems the north bridge is usually
embedded inside of the CPU, also containing the memory and graphics controllers. This
has been implemented by Intel with their ‘Sandy Bridge’ Processors and AMD’s APUs.
The south bridge compared to the north bridge is much slower since it deals with
components such as the hard drives, USB BIOS and PCI slots. You can always tell which
bridge is which since the south bridge is the one that isn’t connected to the CPU directly,
instead the way a south bridge to communicate with the CPU is via the north bridge.
(Source of the image: LINK)
Memory And Backing Store
There are many different ways to store your data or for the computer to store the data it
will need later on so that it can use and refer to it whenever it need to.
RAM
Every computer has what we call random access memory also referred to as RAM. This
type of memory is used by the processor and other computing components via the
processor to store all of the temporary data that it may need to use later on or that it
needs to store as it calculates different calculations. This type of memory is volatile
because as soon as it is unplugged from the computer or the power is cut all of the
memory stored on it will erase itself. RAM has been made in different versions such as
the Synchronous Dynamic Random Access Memory (SDRAM) or the more modern Double
Data Rate Random Synchronous Dynamic Access Memory (DDR SDRAM). Different types
of RAM exist since as the technology advanced and the standards changed different
order of pins had to be arranged which is the reason why we have different types of
memory. Also different types of memory can handle different amounts and speeds of
memory.
Also on every motherboard you can find what we call Read Only Memory also referred to
as ROM. This type of memory is stored somewhere on the motherboard and its function
is to usually store such information as firmware since ROM usually cannot be modified or
modified at a very slow rate which is impractical for such things as storing personal data
or software on. ROM is also a non-volatile memory since your content usually can’t be
changed.
(Source of the image: LINK)
Hard Disk Drives
We also have mechanical storage alternatives such as the Hard Disk Drive (HDD). They
were introduced by a computer company called IBM in 1956 by a team led by Ray
Johnson. Hard drives quickly became the most popular solution for mass storage. In
today’s world hard drives are used in every computer around the world because of their
ability to have a very high capacity all the way up to 4tb per drive. Despite the fact that
the hard drives are so commercial, they work because of the electromagnets and moving
objects making the drives delicate. Hard drives just like motherboards are made in
different form factors. In desktop computer we use the 3.5” drives because they have
the max capacity of 4tb and are not too big to not fit inside of the case. On the other
side companies use the 2.5” drives because they are smaller and slimmer making it easy
to fit inside of a laptop. Those drives come in max capacity of 2tb.
(Source of the image: LINK)
Solid State Drives
Hard drives used to be the leading solution in terms of speed as well however solid state
drives (SSD) were introduced which have a significantly higher speed and are faster than
HDDs. Despite of the name SSDs don’t have a ‘disk’ inside of them; in fact they have no
moving objects inside of them making them more durable than hard drives. Most
commercially used SSDs are in the 2.5” form factor so they can easily be installed in a
laptop or in a desktop computer if you use an adapter bracket. Since the SSDs don’t
have to be solidly installed because they have no moving objects inside some individuals
install them in all kinds of locations inside of a desktop computer, one being behind the
motherboard tray so that the drive isn’t visible. SSD technology has been evolving very
quickly and despite the fact that they are much more expensive to HDDs with the same
capacity they are still preferred by power users such as gamers or heavy software
developers because of their rapid speed both in read and write.
Both HDDs and SSDs are classed as non-volatile memory since their main purpose
usually is to store the user’s data for a longer period of time. In terms of portable
storage solutions we mostly use USB flash drives or portable hard drives which can be
either HDDs or SSDs.
(Source of the image: LINK)
USB Flash Drives
USB flash drives use the USB interface. Inside of the USB hard drive there is a flash
memory chip that holds all of your information and it is all connected to a circuit board
which connects to the USB controller device so that the user can access the chip via the
USB interface. Most but not all USB hard drives have an LED indicator that shows the
activity of the drive.
(Source of the image: LINK)
Portable Hard Drives
Portable hard drives are basically HDDs or SSDs inside of a shell that protects the drive
and connected to a controller which corresponds to the interface it uses to connect to the
computer with. Usual interfaces used in the portable hard drives are USB and sometimes
eSATA. Some hard drives will require external power since the USB won’t be able to
provide enough for the drive to run.
(Source of the image: LINK)
Memory Cards
Lastly, we have memory cards which also come in different sizes depending on their
usage. The most popular types of memory cards are SD, mini SD, micro SD and
Compact Flash. All of these memory cards are usually used in cameras, mobile phones
and other portable devices because of their very compact size and reasonably large
capacity. Memory cards can be connected to the computer either via a internal card
reader or an external one which converts the signal so that it can be transmitted via the
USB interface.
(Source of the image: LINK)
CD/DVD/Bluray Drives and Disks
(Source of the image: LINK)
Compact Disks also abbreviated as CDs. Prototypes were created separately by Sony and
Phillips in mid-late 1970s. After some time both companies joined together to create a
commercially used product in 1982 which is still used by people today. CD disks can hold
up to 700 MB of data unless they are dual layered which effectively would double the
storage size. CD disks were and are mostly used to store audio like your favourite band’s
album or your personal data such as documents and photos. In 1985 CD-ROMs were
created which were made for commercial use since the initial CDs were used for audio
only. Also popular among disk are the CD-RW which are rewritable and reused just like a
USB flash drive.
Digital Video Disk or Digital Versatile Disk also abbreviated as DVD. DVDs were invented
and developed by many companies such as Philips, Sony, Toshiba, and Panasonic in
1995. They were created as an alternative to CDs but to store video such as films. DVDs
come in different capacities. A standard single layered DVD disk has the capacity of 4.7
GB. However we also have the double layered DVD disks which effectively have doubled
the capacity.
Lastly, we have the Blu-ray Disk (BD) which is the newest type of a disk that has been
created to replace the DVD because it have a much higher capacity and can be read
from much faster. Blu-Ray disks were developed by MIT and their Blu-ray Disc
Association which was created with nine leading companies being: Sony, LG Electronics,
Panasonic, Philips, Thomson, Pioneer, Sharp, Hitachi, and Samsung. In 2002 on
February 19th the company announced that they have created the Blu-Ray disk. Just like
the other disk alternatives Blu-Ray disks have a single layered version which has the
capacity of 25 GB and effectively the double layered one has twice the capacity.
Expansion cards
Expansion cards are separate cards that can be inserted into a socket such as the PCI to
connect them into the motherboard and effectively adding additional functionality with
cards such as:
The graphics card is used to render out any animation or 3D object that is being sent to
the monitor as well as it displays any other visual that the computer asks it to, such as
the desktop, an application such as Microsoft Word, etc. Depending on a graphics card
some older and weaker models are only for basic displaying of whatever the computer
tells it to and aren’t so good at 3D and animation however the more expensive and
‘gaming’ or ‘workstation’ oriented graphics cards can do much more complex tasks to do
with graphical rendering and 3D/animation.
The network card is used to receive and send data across an internet cable (e.g. CAT6
Ethernet cable) usually being the internet and all of the data that the computer requests
over it. Network cards and ether net cables can also be used to connect various
computers to each other via a switch creating a LAN connection where you can send and
receive data from the computers that are connected to the switch.
The sound cards can come in different forms with different connectors available. In a
computer you can have a sound card that supports 2.0, 2.1, 5.1, 7.1 channels of audio
and depending on the quality of the product and the components used you can get some
sound cards that produce a much higher quality sound and sound much more clearer
and refined. Also the more higher-end sound cards support more audio enhancing
technologies such as DTS, Dolby True HD or Pro Logic II, etc. All of those technologies
alter the sound so that it either sounds much higher quality or they make it sound more
surround, etc.
Expansion cards are mostly used to enhance the features that the motherboard has with
a higher-end solution or to add extra functionality. The extension cards are inserted so
that they are vertically connected to the horizontal motherboard (considering that the
motherboard is positioned flat).
Connectors
There are different types of connectors that an expansion card can be connected to the
motherboard with. Here are some examples:
ISA
In 1981, company called IBM brought to the market the Industry Standard Architecture
(ISA) which at the time it has become the standard for the expansion cards. This type of
interface could support external data bus of 8 bit for the standard ISA interface and 16
bit for the extended version that was introduced in 1988; this time by a company called
Gang of Nine. Both of the interfaces were gradually discontinued as the PCI interface
was created in 1993.
(Source of the images: http://www.computerhope.com/pictures/mb/isa.gif )
PCI
In 1993, the new standard was introduced by Intel being the Peripheral Component
Interconnect or as usually abbreviated PCI. This standard was a significant leap forward
supporting 32 or 64 bits of external data bus allowing for 133 MB/s transfer speed with a
32bit at 33Mhz configuration, 266 Mb/s transfer speed with a 32bit at 66Mhz or 64 bit at
33mhz and lastly 533 MB/s with a 64 bit at 66 Mhz. This interface was used for all of the
standard expansion cards like sound cards however also used for the graphics cards but
soon overtook in terms of performance by the AGP interface that was specifically
designed for graphics cards and has become the more preferred alternative by the users.
(Source of the image: http://www.computerhope.com/pictures/mb/pci.gif )
AGP
In 1996, the port also developed by Intel, Accelerated Graphics Port more commonly
known as AGP was designed for graphics cards exclusively because of their demanding
needs for data transfer speed. The maximum data transfer speed for this given port are
up to 2133 MB/s giving the graphics cards a lot of room to transfer all of their
calculations in and out of the card. The main advantage for the AGP is that they have a
personal dedicated bus which isn’t limited by any other components unlike on the PCI
slot there all of the cards plugged to the slot share the same bus. This port runs at 66
MHz on a 32 bit wide lane.
(Source of the image: http://www.computerhope.com/jargon/a/agp.jpg )
PCIe
In 2004, Intel along with Dell, IBM and HP designed the successor to the PCI standard
being the Peripheral Component Interconnect Express or in short PCIe. This is the latest
type of standard that is widely used in nearly all modern computers as an expansion
card slot. There are different versions of this slot which use less or more lanes (from 1 to
16)
(Source of the image:
https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/PCIExpress.jp
g/250px-PCIExpress.jpg)
The smaller slots are widely used by less demanding cards such as audio cards and the
larger by heavy duty network cards or graphics cards. With time there were different
versions of this slot however they all looked the same meaning that the new versions
were backwards compatible. With each adaptation of this slot the speed of each slot was
improved gradually. Here are the speeds that were each version of this slot could work
at:
Per lane (each direction):
v1.x: 250 MB/s (2.5 GT/s)
v2.x: 500 MB/s (5 GT/s)
v3.0: 985 MB/s (8 GT/s)
v4.0: 1969 MB/s (16 GT/s)
So, a 16-lane slot (each direction):
v1.x: 4 GB/s (40 GT/s)
v2.x: 8 GB/s (80 GT/s)
v3.0: 15.75 GB/s (128 GT/s)
v4.0: 31.51 GB/s (256 GT/s)
(This information was taken from: https://en.wikipedia.org/wiki/PCI_Express
)
Busses
A computer bus is in some ways like a real life bus it allows you to get from one place to
another however a computer bus allows the data to be transferred from one component
to another allowing them to communicate and compute the data received to then again
send it to another component. Busses can be shared in between various components
inside of the computer. Their purpose is to work a bit like a highway for all of the
components it’s connected to. That way there are less connections required between all
of the components and potentially the data can be transferred at much faster rates.
(Source of the image:
http://static.commentcamarche.net/en.kioskea.net/pictures/pc-images-busschema.png )
Computers have many different busses dedicated for different components. For example
there is a PCI bus which takes care of all of the expansion cards and allows them all to
communicate even if they are not in the same bridge. PCI bus would usually have a lot
of cards connected to it and there would only be one bus for it since there isn’t as much
data going through it to significantly reduce the performance. However much more
important components such as the processor, memory or AGP will have a dedicated bus
for themselves because they will need as much space and speed to rapidly transport
large chunks of data and calculations to the north bridge so that the bridge can direct
the stream of data to another component or out of the computer to the screen.
(Source of the image:
http://static.commentcamarche.net/en.kioskea.net/pictures/pc-images-pcarchitecture.png )
USB
USB is a connector managed by the bus on the motherboard and has been designed in
the 1996 by a group of companies (Digital Equipment Corporation, IBM, Intel, Microsoft,
NEC and Nortel) to become the industry standard for input devices such as a mouse,
keyboard, USB sticks, etc.
(Source of the image: https://en.wikipedia.org/wiki/File:Types-usb_th1.svg)
There have been different types of USB created to fit different purposes. From the
smaller micro and mini connectors widely used on the portable devices such as mobile
phones or cameras ending on ‘standard’ type A and B for devices such as printers. USB
can transmit voltage up to 5v meaning it can power things such as a mini desk fan or an
external hard drive.
With different generations of USB each one got gradually faster however the design is
exactly the same meaning that they are backwards compatible.
(Source of the image:
https://en.wikipedia.org/wiki/File:USB_3.0_Micro_B_plug.PNG)
The newest type of a USB Micro B connector slightly differs in design so that it is able to
transmit the data it needs to.
PS/2
(Source of the image: https://en.wikipedia.org/wiki/File:Ps-2-ports.jpg)
Connector type designed by IBM in 1987 to become the standard for mouse and
keyboard devices. Compared to the USB connectors these were designed to be circular
with pins. The main advantage that is preferred by high end keyboard manufactures is
the fact that via PS/2 you can get N-Key Rollover (Infinite amount of registered keys at
the same time) meaning that every key you press, even if it’s several at the same time
they will all be registered. It was made possible because PS/2 needs to go through less
processes compared to USB to get to the application you are using the keyboard for.
This connector was the same for both mouse and keyboard however you had to connect
it to its destined colour; purple for keyboard and green for mouse.
All of
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the information provided in this unit has been taken as reference from:
http://en.wikipedia.org/wiki/Motherboard
http://en.wikipedia.org/wiki/Processor
http://en.wikipedia.org/wiki/Random-access_memory
http://en.wikipedia.org/wiki/Hard_drive
http://en.wikipedia.org/wiki/USB_flash_drive
http://en.wikipedia.org/wiki/Solid-state_drive
http://en.wikipedia.org/wiki/Memory_card
http://en.wikipedia.org/wiki/Southbridge_(computing)
http://en.wikipedia.org/wiki/Northbridge_(computing)
http://en.wikipedia.org/wiki/Chipset
http://www.wisegeek.com/what-is-a-hard-disk-drive.htm
http://compreviews.about.com/od/storage/a/SSD.htm
http://en.wikipedia.org/wiki/Dvd
http://en.wikipedia.org/wiki/Blu-ray_Disc
http://en.wikipedia.org/wiki/CD
http://en.wikipedia.org/wiki/Heat_sink
http://en.wikipedia.org/wiki/Expansion_card
http://en.wikipedia.org/wiki/Sound_card
http://en.wikipedia.org/wiki/Video_card
http://en.wikipedia.org/wiki/Network_card
http://www.computerhope.com/jargon/i/isa.htm
https://en.wikipedia.org/wiki/Industry_Standard_Architecture
https://en.wikipedia.org/wiki/Extended_Industry_Standard_Architectur
e
 https://en.wikipedia.org/wiki/Conventional_PCI
 http://www.computerhope.com/jargon/p/pci.htm
 https://en.wikipedia.org/wiki/Accelerated_Graphics_Port
 http://www.webopedia.com/TERM/A/AGP.html
 http://en.kioskea.net/contents/375-what-is-a-computer-bus
 https://en.wikipedia.org/wiki/USB
 https://en.wikipedia.org/wiki/PS/2_connector
 http://en.wikipedia.org/wiki/Ethernet
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All of the images have the source below the image. I take no rights for the
creation of the images and they are used for educational use and
demonstrational only.