1.2.2-3 Memory (Secondary Storage) Flashcards
What is secondary storage?
Refers to the devices used to store programs, documents and files.
What does secondary storage need to be?
Needs to be non-volatile
Data capacity + file size
1 binary digit = 1 bit
4 bits = 1 nibble
8 bits = 1 byte
1000 bytes = 1 kilobyte (KB)
1000 kilobytes = 1 megabyte (MB)
1000 megabytes = 1 gigabyte (GB)
1000 gigabytes = 1 terabyte (TB)
1000 terabytes = 1 petabyte (PB)
What are secondary storage characteristics?
Capacity
Speed
Portability
Durability
Reliability
Cost
Characteristics of Magnetic storage?
Ideal for fixed location desktop PCs
Used as larger network storage and backup systems
Ideal for larger document files
Typical capacity = 1-5 TB
Advantages of magnetic storage?
High capacity at low cost
Fast data access
Disadvantages of magnetic storage?
The disk will eventually fail
Easily damages, resulting in corruption of data
Large physical size
Complex moving party’s increases power requirements
Characteristics of optical storage?
Ideal for portable systems
Often used for storing commercial and personal music, videos and games
Wide range of capacities
(CD 700MB, DVD 4.7-9.4GB, Blu-ray 25-128GB)
Advantages of optical storage?
Cheap to manufacture
Very portable
Widely available
Disadvantages of optical storage?
Discs can be damaged easily and degrade over time
Limited capacity
Compatibility issues between players
What does SSD stand for?
Solid state drive
Common applications for SSD’s?
USB portable drives
Smartphone and tablet memory
Digital camera and video camera memory
Game console memory expansion
High-end desktop computers
Advantages of SSD’s?
Use significantly less power than magnetic hard drives
Faster read/write access than magnetic storage
Small size
No moving parts
Ideal for USB and other portable devices
Disadvantages of SSD’s?
More expensive per GB than magnetic or optical storage
Can wear out over time
Capacity typically less than 2TB
How is data stored?
Magnetically, optically or electronically using a SSD.
