1.2 - Memory and Storage

Question 1

What does primary storage consist of?

Answer 1

• Random Access Memory (RAM)
• Read Only Memory (ROM)
• Registers & Cache

Question 2

Why do we need primary storage?

Answer 2

• It holds the data and instructions which the CPU needs to access while a computer is running
• The CPU can access data from primary storage much more quickly than secondary storage

Question 3

What is the difference between RAM and ROM?

Answer 3

RAM:
- Volatile
- Read and write
- Larger
ROM:
- Non-volatile
- Read only
- Smaller

Question 4

What is the purpose of RAM?

Answer 4

• Holds the operating system, programs and data in use by the CPU when the computer is running

Question 5

What is the purpose of ROM?

Answer 5

• Holds the first instructions for when the computer is first turned on, known as the bootstrap

Question 6

Why is virtual memory needed?

Answer 6

• Virtual memory is needed when there isn’t enough physical RAM to store the open programs

Question 7

How does virtual memory work?

Answer 7

• Programs are transferred to virtual memory from the RAM when there are not being executed
• Programs are transferred back to RAM from virtual memory when they are needed

Question 8

Why do we need secondary storage?

Answer 8

• It’s needed for;
  – Storage of programs and data when the power is turned off
  – Semi-permanent storage of data that can change
  – Backup & archive of data files

Question 9

What are the common types of storage?

Answer 9

• Optical (CD, DVD, Blu-Ray)
• Magnetic (Hard disk drive, tape)
• Solid State (SSD, Memory sticks, Flash memory cards)

Question 10

What are the advantages of optical storage?

Answer 10

Thin, lightweight & portable

Question 11

What are the disadvantages of optical storage?

Answer 11

Low capacity
Slow to access data

Question 12

What are the advantages of magnetic storage?

Answer 12

High storage
Quick to access data

Question 13

What are the disadvantages of magnetic storage?

Answer 13

Has moving parts which eventually fail
Hard disks perform better if defragmented

Question 14

What are the advantages of solid state storage?

Answer 14

Medium storage
Very quick to access data
No moving parts, reliable
No noise
Low power
No defragmentation needed

Question 15

What are the disadvantages of solid state storage?

Answer 15

Limited number of read/write cycles
Expensive