Hard disk

Presented By:Sajid KhanECN 1st Sem

Presented to:Dr. Manju K. Chattopadhyay

A Presentation On

Content1 – Introduction2 – History3 – Working4 – Characteristics5 – Need for a Proper Shutdown6 – Types 7 – Tracks and Sector8 – How Data Is Organized On Disk9 – Disk Partitions10 – Partitions11 – Size Measurement and Actual Capacity12 – Market Values and Prices13 - Manufacturers 14 –SATA versus PATA

A hard disk drive is a non-volatile storage device that stores digitally encoded data on rapidly rotating rigid platters with magnetic surface.

Introduction

Hard disk was first introduce in 1956 as data storage for an IBM accounting computer and were originally developed for use in personal computers.

History

WorkingHDD records data by magnetizingferromagnetic material directionally,to represent either a 0 or a 1binary digit. They read the data back by detecting the magnetization of the material.

Characteristics

1- Data Transfer Rate (Bytes / Second)2- Seek Time (Second)3- Power Consumption (Watt) 4- Shock Resistance

Need for a Proper Shutdown

Before plug off computer we need a proper shutdown. But Why????

Because in hard disk head is separated from platter by air force. In case of power failure air force is absent and the head fall down onto the platter this may crash the platter and the data recorded on that area may be lost.

Types :-Now a days Two types of hard disk is common in use. 1- IDE or PATA (Parallel Advanced Technology Attachment )2- SATA(Serial Advanced Technology Attachment )

SATAPATA

Sector =small arc of track

Track=concentric

circle

Can store 512 bytes

Tracks and sectors

How Data is Organized on Disk

• Tracks-

– circular areas of the disk

– Data first written to outer most track

• Sectors-

– Divides tracks sections

• Cylinders-

– Logical groupings of the the same track on each disk surface in a disk unit

Partitions

Divides hard drive into logical subdivisions which are seen by the operating system as separate logical hard disks. Hard drives divided into primary and extended partitions. The primary partition boots the system.

Size Measurement

Actual Capacity

0.93 x Capacity by manufacturer0.93 x Capacity by manufacturer

Number of cylinders by number of heads by number of sectors by 512

Number of cylinders by number of heads by number of sectors by 512

Market Value & Price

• Hard disk is one the most purchased spare. In 2009 516.2 Millions hard disk were sold

Capacity Price Type

2 TB 12,000 Rs SATA

500 GB 4,750 Rs SATA

1.5 TB 6,900 Rs SATA

250 GB 2,000 Rs SATA

160 GB 2,050 Rs PATA

Manufacturers

• Seagate

• Western Digital

• Hitachi

• Samsung

• Toshiba

PATA AND SATA CABLES

SATA CABLEPATA CABLE

0

20

40

60

80

100

120

140

160

180

200

Speed Length Pins Easier

SATA PATA

SATA V/S PATA

Any Query

Don’t be confused ask to us