Storage technologies

Question 1

Storage

What does secondary storage do?

Answer 1

It provides a way of keeping copies of data and programmes for use at a later date

Question 2

Storage
If main memory can be volatile, offer small amounts of capacity (a few GB) but be easily and directly accessed by the CPU, how is Secondary Storage different?

Answer 2

Secondary storage is non-volatile, it has large capacity (up to a TB) but is not directly accessed by the CPU

Question 3

Storage

what are the three different types of technology used for storage media?

Answer 3

Magnetic storage
Optical storage
Solid state or flash storage

Question 4

Magnetic Storage
Magnetic storage uses minute magnetic particles or ‘domains’ to store data.
Give three examples of magnetic storage

Answer 4

Hard disk
Magnetic tape
Floppy disk (now obsolete)

Question 5

Magnetic Storage

what does magnetic storage uses to store data?

Answer 5

Minute magnetic particles or ‘domains’

Question 6

Magnetic storage

What are three advantages of magnetic storage?

Answer 6

1) huge capacity - measured in Terabytes (TBs)
2) cheapest of the options in terms of storage cost per GB
3) Data can be stored for a long time

Question 7

What does TB stand for?

Answer 7

Terabyte

Question 8

Magnetic storage

What are four disadvantages of magnetic storage?

Answer 8

1) Magnetic fields can corrupt or damage the stored data
2) It isn’t as portable as other technologies (it is heavier than CD and if it is physically integrated into a computer then it would need to be physically removed to carry it around)
3) Hard disks have moving parts and these can wear out over time
4) It is slower to access the data on magnetic storage than on solid state disk using flash technology

Question 9

Optical Storage

Give three examples

Answer 9

CD
DVD
Blue Ray disks

Question 10

Optical Storage

How is data recorded and how is binary used

Answer 10

A laser beam burns tiny dark pits onto the surface of an optical disk.
If a pit is present the data value is 1, if no pit is present then the data value is 0

Question 11

Optical Storage

Give three advantages

Answer 11

1) Very portable, esp compared to a hard disk
2) cheap for limited amount of data storage - up to say 10 GB
3) it is immune to magnetic fields, unlike how magnetic media can be damaged byt magnetic fields

Question 12

Optical Storage

Give three disadvantages

Answer 12

1) It is not as robust as magnetic or solid state media and disks can be scratched or broken
2) it is slower to write to than other media and it is slower to read / access data from than a solid state or magnetic hard disk
3) although it is inexpensive for slammer amounts of data (a few GB) the cost would be too high for large data (TBs)

Question 13

Solid State / Flash

Give three examples

Answer 13

1) USB memory stick
2) Solid State Drives (SSD)
3) Memory card for digital cameras
4) Mobile phones
5) Video game hardware

Question 14

Solid State / Flash
How is data held?
how is binary used?

Answer 14

Using electronic switches

if closed it is a 0 and if open then it is a 1

Question 15

Solid State / Flash

Give three advantages

Answer 15

1) very portable compared to other tech
2) It is robust - no moving parts to damage
3) It is faster to access than a magnetic hard disk

Question 16

Solid State / Flash

Give two disadvantages

Answer 16

1) SSD are expensive compared to an equivalent magnetic hard drive
2) There are a limited number of erase / write cycles

Question 17

Storage
In an exam you will be asked to compare and recommend storage solutions.
What should you take into account?

Answer 17

CAPACITY - (DVD or USB for up to 10 GB, magnetic tape for TBs)
SPEED - (flash is fastest and magnetic tape slowest)
PORTABILITY (USB is most and internal hard disk is least)
DURABILITY - (Flash is most, CDs and DVDs are least)
RELIABILITY - (magnetic tapes most, solid state flash least)
Cost (magnetic storage cheapest, CDs/DVDs are most expensive)