IT 100- 08 IT Fundamentals Lecture 3Computer Systems

During the Second Lecture …

We talked about the evolution of computers

How initial computers were mechanical, and then came electro-mechanicals, then tube-based, and finally transistor based, and how the future belongs to quantum computers

We discussed how the size is drastically decreasing with time and how their capability is increasing year by year

Today’s Goal

1. To learn to classify computers according to their capability and targeted applications

2. To find out about the essential building blocks that make up a modern computer

Performance is judge by the:

Amount of data that can be stored in memory

Speed of internal operation of the computer

Number and type of peripheral devices

Amount and type of software available for use with the computer

Computer Types According to Capability

Supercomputers

Mainframes

Servers

Desktops

Portables

Supercomputers (1)

State-of-the-art machines designed to perform calculations as fast as the current technology allows

Used to solve extremely complex and large-scale problems: weather prediction, simulation of atomic explosions; aircraft design; movie animation

Cost tens of millions of dollars

Unique in that unlike mainframes & personal computers, designed to focus all their resources and capabilities on a single task at a time

Supercomputers (2)

Early supercomputers used a single or a few processors working in parallel

Those processors were custom-built for the supercomputers, and were, therefore, very expensive

Modern supercomputers use the same processors that are used in desktop PCs. They, however, are designed to use 1000’s of them working together in parallel

Why use many not-so-powerful processors working in parallel

Why not just design a single, really powerful processorPost your answers on YG

?

?

Processor board of a CRAY YMP vector computer

The Champion: ASCI White Most powerful computer as of February

2002 Capable of 12.3 trillion calculations/sec

74,000 times faster than Cray 1 (1976) 1,000 times faster than Deep Blue (1997)

Designed for complex 3-D simulations required for testing nuclear weapons

Powered by 8192 microprocessors 6 TB of memory; 160 TB of storage

capacity

Jaguar : Cray XT5

As of June 2010, Jaguar is the world's most powerful computer according to TOP500.

Peak performance of just over 1750 teraflops (1.75 petaflops)

Has 224, 256 Opteron processor cores

Operates with a version of Linux called Cray Linux Environment.

300TB of memory;

Mainframe Computers (1)

Also called “Enterprise Servers”

Designed for performing multiple, intensive tasks for multiple users simultaneously

Used by large businesses (e.g. banks, e-commerce sites), military, and industrial organizations

Mainframe Computers (2)

Designed for very-high reliability

Can be serviced/upgraded while in operation

Generally consist of multiple processors, GB’s of memory, and TB’s of storage

Cost in millions of dollars

Servers/Minicomputers (1) The name minicomputers used to

define the class of computers that lies between personal computers and mainframes

Then very high-end desktop computers – called low-end or mid-range servers – took over the role that was previously played by minicomputers

Servers/Minicomputers (2)

Low-end and mid-range servers are used by small businesses and organizations as file-stores, to run e-mail systems and Web sites

Generally are more reliable than desktops, but not as solid as the mainframes

Generally consist of 2 or more processors, GB’s of memory, and TB’s of storage

Costs in hundreds of thousands of dollars

Desktop Computers (1)

Also called microcomputers

Low-end desktops are called PC’s and high-end ones “Workstations”

Generally consist of a single processor only, some times 2, along with GB’s of memory, and GB’s of storage

Desktop Computers (2)

PC’s are used for running productivity applications, Web surfing, messaging

Workstations for more demanding tasks like low-end 3-D simulations and other engineering & scientific apps

Are not as reliable and fault-tolerant as servers

Workstations cost a few thousand dollars; PC around a $1000

Mobile Computers (1) Laptops, palmtops, and wearable computers

are very capable computers but are light-weight and consume very little power

Laptops (also called notebook computers) generally weigh around 2kg, use special low-power processors, typically have 1GB memory, 320GB of storage, can work for more than 2 hours on battery

Their usage is similar to that of PCs

They cost in the range of $1500-2500

Mobile Computers (2)

Palmtops, also known as PDA’s - Personal Digital Assistants

Weigh less than a pound, have very low-power processors, KB’s of memory, MB’s of storage capacity

Can run for many hours on AA batteries

Used as an electronic version of a pocket diary. Also for Web surfing and e-mail or even as mobile phones

Palmtops cost $200-600

Mobile Computers (3)

Wearables are small in size, carried in a pocket, worn on the arm, waist, or head or elsewhere on the body

Capability similar to PDA’s, but more expensive

They are always ON, and always accessible. That is, the user can always enter and execute commands, even while walking around or doing other activities

Each soldier of the future will be fitted with one

Picture of a wearable computer

Ranking w.r.t. installed number

PC’s PDA’s Workstations Servers Wearables (will take the top spot in

future) Mainframes Supercomputers

Now that we have learnt about the various types of computers and about their typical applications, let’s move on to a new topic

Let’s now find out about the essential components that are present in every type of computers

At the highest level, two things are required for computing

Hardware: The physical equipment in a computing environment such as the computer and its peripheral devices (printers, speakers, etc.)

Software: The set of instructions that operates various parts of the hardware. Also termed as “computer program”

We’ll have a lot to say about software during the duration of this course

However, for the rest of today’s discussion, let’s concentrate on hardware

All computers have the following essential hardware components:

Input – the component through which a user instructs a computer about what to do

Processor – the engine that processes the instructions given by the user

Memory – where the processor stores information that is required during its computations

Storage – where information that is required to be used much later is stored

Output – the component that communicates the results of a computation to the user

There is another quite essential component that is present in every computer …

????

The Bus!

Keyboard Mouse

PrinterMemory

HardDisk

MemoryBus

System Bus

Monitor

CompactDisk

Processor

IntegerUnit

ControlUnit

CacheMemory

FloatingPointUnit

Input Devices

Mouse Keyboard Joystick Camera Micropho

ne Scanner

What’s a Port?

Port

The connection point at which we connect input and output devices to a computer

Many Types of Ports

1. Parallel2. Serial3. SCSI4. USB5. Firewir

e

Processor

Pentium Celeron Athlon PowerPC StrongARM (PDA) Crusoe (Laptops) SPARC

(Workstations)

Memory/Storage

RAM Punch cards ROM Hard disk Floppy disk Tape CD DVD

Classifying Memory/Storage

Electronic (RAM, ROM)magnetic (HD, FD, Tape), optical (CD, DVD)

Volatile (RAM), non-volatile (HD)

Direct access (RAM, HD), serial access (Tape)

Read/write (HD, RAM), read-only (CD)

Output Devices

Printer

Plotter

Speakers

Monitor

modeminput device or output device?

modem

modulatordemodulatorom demmodem

Modem is an example of a device that acts both as an input as well as an output device

Can you think of any other such dual-purpose devices?

Network card Touch screens

What have we learnt today?

What are the various types of computers with respect to their size, capability, applications (FIVE TYPES)

The five essential components of any computer are input devices, processor, memory, storage and output devices

Next time we’ll find out about

1. What are the major building blocks of a modern personal computer?

2. How those building blocks are put together to form a PC?

Firewire

Parallel Port

Serial Port

USB Port