Storage Devices Flashcards
What is the difference between primary and secondary storage?
Primary storage (RAM) is volatile and fast, while secondary storage (HDD, SSD) is non-volatile and used for long-term storage.
Name two types of secondary storage.
Magnetic storage (HDD), Optical storage (DVD, Blu-ray), Solid-state storage (SSD, USB).
What is an advantage of solid-state drives (SSD)?
Faster data access speed, no moving parts, more durable.
Why are DVDs not ideal for large-scale backups?
They have limited storage capacity and slower data transfer speeds.
Computer storage (ROM)
- Non-volatile
- Fixed during
manufacturing - Bootstrap Loader
Computer storage (RAM)
- Volatile
- Currently running
programs
MAGNETIC STORAGE MEDIA
Logic 0 and logic 1 are stored as the absence or presence
of a magnetic spot
Head of disk is electromagnetic
Creates a pattern of magnetised and non-magnetised
areas on disk
HARD DISKS
Internal
Fast access
Large capacity
Sealed
Uses Store Operating System Store application software Store user’s file
Disks spin quickly
Disk heads are positioned very close to the disks but
do not touch
Several physical disks which make up the hard disk
unit are known as a platter
HARD DISKS – READING AND WRITING
- Seek
Move head to proper track
Seek time: ms - Rotate
Rotate disk to correct sector
Rotational delay: ms - Settle
Lower heads to disk, wait for vibrations from moving to stop
Settling time: ms - Data Transfer
Copy data to main memory or write to disk
Transfer rate: kbs
OPTICAL STORAGE MEDIA
Logic 0 and logic 1 are written using laser light. The pattern of reflected light (pit) and non reflected light
(land) creates a code that represents data
DVD
Digital Versatile Disk
Portable
Shorter wavelength
Can store on both sides
Greater capacity
BLU-RAY DISK
Portable
High definition
50GB
Shorter wavelength
SOLID STATE MEDIA
Saves data through electricity
Data is saved through circuit board and chips
Connected through a USB port
Flash memory
Portable and durable
Easily lost, stolen or damaged
SD CARD
Digital cameras
Mobile phones
Game consoles
Card reader may be needed
SOLID STATE HARD DISK (SSD)
Microchips
Faster than magnetic hard disk
No moving parts
Embedded controller
More expensive
