Data Storage

Question 1

RAM stores

Answer 1

• Data and instructions currently in use
• Part of Operating System currently in use
• Utility system currently in use
• Application software currently in use

Question 2

RAM characteristics

Answer 2

• Temporary memory device
• Can be written to and read from
• Volatile

Question 3

what does cache store

Answer 3

• store frequently used instructions and data.

Question 4

Cache characteristics

Answer 4

• Cache has faster read/write speeds than RAM
• Increase the amount of cache = increase performance of computer
• VOLATILE, ALL data will be lost if computer is switched off

Question 5

ROM store:

Answer 5

• stores the start-up instructions
• store the BIOS

Question 6

ROM charactertistics

Answer 6

• Permenant memory device
• Non-volatile
• Only read memory, data cannot be written to rom

Question 7

RAM technology:

Answer 7

SRAM (static RAM)

DRAM (dynamic RAM)

Question 8

DRAM characteristics

Answer 8

• Consists of transistors and capacitors
• Needs to be constantly refreshed
• The main memory is constructed from DRAM

Question 9

DRAM adv over SRAM

Answer 9

• less expensive to manufacture than SRAM
• consume less power than SRAM
• higher memory capacity than SRAM

Question 10

SRAM characteristics

Answer 10

• uses flip flops to hold each bit of memory
• doesn’t need to be constantly refreshed
• has a faster data access time than DRAM
• CPU memory cache makes use of SRAM

Question 11

Primary Storage characteristics

Answer 11

• Directly accessed by the CPU
• Can be volatile or non-volatile
• Contains RAM, ROM, and Cache memory
• Shorter data access time than secondary

Question 12

Secondary and offline storage characteristics

Answer 12

• Not directly accessible by the CPU
• Non-volatile
• Can be external or internal to computer
• Can store more data than primary
• Longer data access time than primary

Question 13

Types of secondary and offline storage

Answer 13

• Magnetic
• Solid State
• Optical

Question 14

Hard Disk Drive
(MAGNETIC): How it stores data:

Answer 14

• Data is stored on platters which is divided into sectors and tracks
• Has components that are spun
• Data is read/written using a read/write arm which moves over the surface of the disc
• Data is read/written using electromagnets.

Question 15

CD (OPTICAL): How is stores data

Answer 15

• Uses thin layer of metal alloy to store data
• Uses single spiral track which runs from centre to edge of disk
• Data is stored in pits and lands on spiral track
• red laser is used to read and write the data

Question 16

Solid State Drives (SOLID STATE): How it stores data

Answer 16

• Uses transistors and NAND/NOR technology
• Uses NAND or NOR gates to control the flow of electrons
• Stores data by flashing it onto chips
• When data is stored the transistor is converted from 1 to 0 / 0 to 1

Question 17

Virtual Memory

Answer 17

When RAM is overloaded, the Operating System uses part of the hard drive (HDD) to design a temporary area of memory called virtual memory

Question 18

Purpose of virtual memory

Answer 18

Prevents the computer system crashing when RAM is full

Question 19

Why is VM slower than RAM

Answer 19

Data access time is slower since data travels further to CPU to be processed

Question 20

Benefits of virtual memory

Answer 20

• Reduces need to buy and install more expensive RAM
• Programs can be larger than physical memory and still be executed

Question 21

What VM stores

Answer 21

VM stores the inactive, less demanded pages
while RAM stores the more active demanded pages
when inactive page is needed, it is transferred from VM to RAM

Question 22

Cloud Storage Meaning

Answer 22

a collection of servers that store data in a remote location by a third party, and are accessed using an internet connection.

Question 23

Advantages of cloud storage

Answer 23

• Accessibility - data can be accessed from anywhere through internet connection
• hardware owned by a third party ( company is not responsible for maintaining and security)
• Scalability - cloud storage providers allow customers to increase or decrease their storage capacity as needed , without needed to buy new hardware
• Reliability - cloud system often use multiple servers to store and backup data, reducing the risk of data loss due to hardware failure, company does not need to do it

Question 24

Disadvantage of Cloud storage

Answer 24

• Slow or unreliable internet connection, they would have problems accessing their files
• Data can be intercepted , may be less secure
• Security managed by the cloud storage provider - user does not have complete control over it

Question 25

DVD differences from CD (OPTICAL)

Answer 25

DVD uses Dual layering technology, which increases storage capacity, as there are two indivdual recording layers

Question 26

Flash memory (OFFLINE SOLID STATE TECHNOLOGY)

Answer 26

• Connect to computer using USB port
• Advantage: very small, lightweight, portable devices.
• Suitable for transferring files between computers
• Can be used as backup devices for media files

Question 27

Advantages of SSD

Answer 27

• Large capacity storage
• No moving parts (Durable)
• Faster access speed than HDD
• Uses less power HDD
• Does not take time to start-up
• Run quieter than HDD

Question 28

Advantages of HDD

Answer 28

• Large capacity storage
• Longevity
• cheaper than SSD per GB

Question 29

What is offline storage

Answer 29

• non-volatile
  − Can be easily disconnected from the computer
  − It is not directly accessed by the CPU
  − e.g CD, DVD, USB flash memory

Question 30

Blu Ray differences vs DVD

Answer 30

• DVD uses red laser, blu-ray uses blue laser
• DVD has a smaller storage capacity, Blu-ray has a larger storage capacity
• DVD has two layers of polycarbonate , Blu-ray disks have a single layer of polycarbonate
• DVD has a slower transfer rate , Blu-ray has a faster transfer rate