CST8174_Lecture_8_Introduction_to_hard_drives

CST8174_Lecture_8_Introduction_to_hard_drives - Algonquin...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
May 7, 2009 Matthew O’ Meara 1 - 1 Algonquin College CST8174 CST8174 Computer Technology Basics Hard Drives
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
May 7, 2009 Matthew O’ Meara 1 - 2 Algonquin College CST8174 Hard Drives The hard drive is the main storage device for all modern computers The initial PC’s did not provide support for hard drives, only floppy drives The first hard drives were extremely slow and not very reliable Modern hard drives are much faster and very reliable
Background image of page 2
May 7, 2009 Matthew O’ Meara 1 - 3 Algonquin College CST8174 Hard Drive Advancements Storage capacity Originally 5MB Now up to 400GB This is 80,000 times larger Data transfer rates Originally 85Kbps Now as fast as 320Mbps Almost 3,800 times faster
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
May 7, 2009 Matthew O’ Meara 1 - 4 Algonquin College CST8174 Hard Drive Advancements Seek time First hard drives around 85ms Now down to 3.2ms Over 26 times faster Cost $2,000 for 10MB Now $70 for 250GB A minute fraction of the cost
Background image of page 4
May 7, 2009 Matthew O’ Meara 1 - 5 Algonquin College CST8174 Inside a Hard Drive
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
May 7, 2009 Matthew O’ Meara 1 - 6 Algonquin College CST8174 Inside a Hard Drive Some major internal components of a hard drive Platters Recording media Read/write heads Actuator arms Spindle Motors Air Filters
Background image of page 6
May 7, 2009 Matthew O’ Meara 1 - 7 Algonquin College CST8174 Inside a Hard Drive Platters Hard drives use rugged and solid platters to store data Platters were traditionally made of aluminum and coated with a magnetic medium Newer platters are now made from a ceramic composite material These are lighter and have very low thermal expansion
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
May 7, 2009 Matthew O’ Meara 1 - 8 Algonquin College CST8174 Inside a Hard Drive Recording Media All platters must be covered with a thin layer of a magnetically retentive substance Oxide media Soft, cheap and not capable of store large amount of data Thin-film media Thinner, harder and more perfectly formed Very smooth, allowing heads to float closer AFC media Called antiferromagnetically coupled media
Background image of page 8
May 7, 2009 Matthew O’ Meara 1 - 9 Algonquin College CST8174 Inside a Hard Drive Read/write heads Both sides of each platter is coated to provide separate magnetic surfaces Every platter requires two read/write heads, one for each side The read/write heads are spring loaded and will make contact with the platters at rest They do not make contact with the platter during use, they float on a very thin cushion of air The air buffer is less than 15 microns, by comparison a finger print is 30 microns
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
May 7, 2009 Matthew O’ Meara 1 - 10 Algonquin College CST8174 Read/Write Head
Background image of page 10
Matthew O’ Meara 1 - 11 Algonquin College CST8174 Inside a Hard Drive Actuator Arm The read/write heads are located on the tip of the actuator arm The actuator arm is moved by one of two types of motors Spindle
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 40

CST8174_Lecture_8_Introduction_to_hard_drives - Algonquin...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online