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Flashcards in 1.3 Storage Deck (27)
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1

What are the three tiers of storage?

Primary
Secondary
Tertiary

2

Define primary storage.
Give four examples

Memory areas that the CPU access is directly and quickly. Has the fastest read/write speeds and is mostly volatile

This includes registers, cash, ROM and RAM

3

Define secondary storage

Nonvolatile, read/write, permanent memory which is not directly accessed by the CPU, and his data must be transferred into main memory before being processed by the CPU

4

Define tertiary storage

External, non-volatile, high capacity memory used for archives and backups by large companies

5

Give a typical example of tertiary storage

A magnetic tape library which may use a robotic arm to access the tapes

6

Why is secondary storage required?

A way of storing data and files permanently and long-term – must be non-volatile and read/writeable

7

How is data stored on optical discs?

As microscopic indentations (pits and lands representing 0s and 1s) on a disc’s reflective surface in a spiral track running from inside to outside of disc

8

What is the capacity of a CD? DVD? BD?

CD = 700 MB
DVD = 4.7 GB
BD = 25 GB +

9

Why are optical discs falling out of use?

Streaming and downloading as internet speeds have increased remove the need for optical discs

Modern devices such as smartphones don’t have optical drives

Can’t compete with flash memory for backups – low capacity, slow read/write speed and poor reliability of read/write discs

10

How is data stored in magnetic storage?

As opposite magnetic polarities in sectors within tracks on a magnetise metal platter, which makes up one of many stacked on top of each other, spinning at 5400 - 15000 rpm

11

What is the traditional internal storage for a computer?

HDDs

12

What is a read/write head made of?

Electromagnets

13

What are the advantages of SDDs over HDDs?

Faster
Don’t need defragmenting
No noise
No heat
More shock-proof

14

What is flash memory?

Data is stored in arrays of transistors, which are either on or off, representing zeros and ones

15

Faster boot up times and faster opening of programs and files is given by ...

Solid state storage

16

What is the physical appearance of magnetic tape? What does it require?

Comes in plastic cassettes which require a special tape-drive to read/write

17

How is data written into magnetic tape?

Sequentially

18

What happens if an HDD is hit?

The data is corrupted when the head hits the platters

19

Reliability of optical discs

Stored data degrade over time

20

Data access time of HDDs

Milliseconds

21

Data access time of SDDs

Nanoseconds

22

How is data accessed on an HDD?

Random Access

23

Cost of optical discs

Very low

24

Why is the cost of solid state so high?

Relatively young technology

25

Capacity of a typical HDD

1 - 2 TB

26

Capacity of a typical SDD

128 - 512 GB

27

What percentage overheads do you need when calculating data capacity?

When do we use this in our calculations?

10%

Only use if the question specifies