slide no: 1 st3520 l2 mt hardware - 1: components of a computer

Slide no: 1 ST3520 L2 MT

Hardware - 1:Components of a Computer


ObjectivesThe objectives of this session (three lectures) are to:

define the nature of data and information

describe how computers represent data

define the principal physical components of a computer system.

describe in broad terms how each component works.

describe the operating/performance characteristics of each component.

show how these components inter-relate.

look at trends in current technology

give you a sufficient understanding of the technology to underpin your understanding of Information Systems


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What is Data? Definitions:

A series of non-random symbols, number, values or words.

A series of facts obtained by observation or research

A collection of non-random facts

The record of an event or fact

Examples:

today’s date;

measurements taken on a production line;

records of business transactions.


What is Information? Definitions:

Data that has been processed so that they are meaningful.

Data that has been processed for a purpose.

Data that has been interpreted and understood by the recipient.

Examples:

A bank statement;

A sales forecast;

A telephone directory.

Information Warfare


Components of a PC Hardware System

You put something in

The computerdoes something to it

You getsomething out

The computer maystore it for a while

Input Processing Output

Storage

DATA INFORMATION


Word Count on a Word Document

The computerdoes something to it

The computer maystore it for a while

Word Document +

Program Instructions

CountingNumber

ofWords

Pop-up windowwith

Word Count

StoreDocument

Running TotalProgram Instructions

DATA INFORMATION


Components of a PC Hardware System

Input Devices•Keyboard•Mouse

CentralProcessingUnit (CPU)

Output Devices•Printers•Video display

PrimaryStorage

CommunicationDevices

Secondary Storage•Magnetic disk•Optical disk

Buses


How Computers Represent Data Bit Byte Size is normally expressed in Bytes Standard measures are:

1,024 bytes = 1 kilobyte (KB) (1,024 = 2 x2 x 2 x2 x 2 x 2 x 2 x2 x 2 x2)

1,024 KB = 1 Megabyte (MB) 1,024 MB = 1 Gigabyte (GB) 1,024 GB = 1 Terabyte (TB) 1,024 TB = 1 Petabyte (PB) 1,024 PB = 1 Exabyte (EB) 1 EB is approximately 1,000,000,000,000,000,000 bytes.

Today PC memory is measured in Megabytes, PC disk in Gigabytes and mainframe disks in Terabytes.


Some Sizes


However... When talking of:

Processors (CPU) and Communications use bit.

A 56.8 Kbps modem means 56,800 bits per second

= KB

Processors are often described as 8, 16, 32 or 64 bit.


The Central Processing Unit (CPU)

InputDevices

SecondaryStorage

OutputDevices

ControlUnit

PrimaryStorage

ALU

Registers

The CPU

Instruction Set


Core components

Control Unit

Arithmetic-Logic Unit

Registers

Instruction Set

Clock

Primary Storage

Optional

Cache

The Central Processing Unit (CPU)


The CPU (continued) Control Unit

Access program instructions

Decode (interpret) instructions

Control flow of data throughout system

Data flows through paths called buses

Arithmetic-Logic Unit

Perform computations on data

Perform comparisons on data

Registers

High speed storage areas

Hold data and instructions


The CPU (continued) Instruction Set

Pre-programmed functions

Clock

Sequences events

Primary Storage (Main Memory)

Stores instructions from programs

Stores data to be processed

Cache Memory (optional)

Overheats – Heat sync

Iitac


Speed of a Chip1. Cycle Speed

Clock speed – beat frequency of the clock (in MHz) determines how many times per second the processor performs operations.

Intel® Core™ 2 Duo E4400 Processor (2.0GHz,800MHz,2MB cache) – 2 billion cycles per second

2. Word Length

No. of bits that can be processed at any one time.

Pentium D processes 64 bits of data in one machine cycle.


Speed of a Chip3. Data Bus Width

The physical paths down which the data and instructions travel.

The wider the bus the more data can be moved – faster!

Bus bandwidth: The product of the width of its bus (in bits) times the frequency at which the bus transfers data (MHz).

3. Line width

Distance between transistors (the smaller this is the more transistors can fit on the chip)


The Microprocessor

Silicon on a ceramicbase

Contains thebasic processingfunctions

The Intel Pentium D is one exampleIt is the latest generationof a series that started with 8086 c. 1978.

Approximately100 pins to linkto remainder ofcomputer

Uses 64 bitregisters Intel Compatibles

Advanced Micro Devices (AMD)Cyrix Corporation


Examples of Microprocessors

Name Manufacturer Word length Data Bus Width

Used In

Pentium 4 Intel 32 64 PCs

Pentium D Intel 64 64 PCs

Athlon AMD 64 64 PCs

Pentium Xeon Intel 64 64 PCs

UltraSPARC IV Sun Microsystems 64 64 Workstations


Getting More Performance Instruction sets

Complex Instruction Set Computer or CISC. Intel x86, Pentium

Reduced Instruction Set Computers (RISC) Power PC

Very Long Instruction Word (VLIW) Intel Itanium

Explicitly Parallel Instruction Computing Intel Pentium 4


Multiple Processor Machines

TASK 1

RESULT

TASK 2

RESULT

Program

CPU

Program

CPU

Program

CPUTASK 2

CPUTASK 3

CPUTASK 1

RESULT

SEQUENTIAL PARALLEL

MASSIVE PARALLEL COMPUTERS CAN HAVE THOUSANDS OF CPUs TO ATTACK LARGE COMPUTING PROBLEMS


Other Chips

CPUs alone do notrun a working

computer

Other chips areneeded. Some contain startupinformation, instructions

Specialisedchips include:•Video memory•Graphics processing•Encryption•Language compilers•Floating point arithmetic

Standard chipsare found on

the motherboard

Specialised chipsare often on

daughterboards


PC 1991


PC 2007


Primary Storage

Stores data and program statements for the CPU

Data that have been input before being transferred to the ALU.

Data and results during intermediate stages of processing.

Data after processing until being transferred to an output device.

Program statements/instructions received from input devices and secondary storage.


RAM (random access memory) Where the CPU stores the instructions and data it is processing.

Size (1.0GB for multimedia)

Speed

Address

Memory is an array of silicon based binary switches

Volatile

Virtual memory


Cache Memory Temporary storage for frequently used blocks of programmes.

High speed.

Primary (Level 1 cache) – located in the processor.

Secondary (Level 2 cache) – located on the motherboard.


ROM (read only memory) Portion of Primary Storage that cannot be changed or erased.

Nonvolatile

Booting up

BIOS

POST


Storage Speeds

Level 1 CacheLevel 2 Cache

ExpensiveCheap

Small AmountLarge Amount


TO DO!!

What is Grid Computing, how does it work, where is it used?


Summary of Key Points Computers comprise input, output, storage and processing

devices.

Computers are made up of many components of which the most important is the Central Processing Unit.

Processor performance depends on:

Register size;

Clock speed;

Bus size;

Line width.

Currently processors are mostly 64 bit.

There is a steady trend toward multiprocessing machines.

slide no: 1 st3520 l2 mt hardware - 1: components of a computer

Documents

data r

information r

r definitions

r byte r size

r information warfare

mb cache r

sizes slide

fact r examples