Secondary Storage 1.2 Flashcards
Secondary storage
-stores data for long periods of time
-robust/reliable
-much cheaper per MB than main memory
-more capacity
-portable
Solid-state storage meaning
-has no moving parts (solid)
-stores data inside electronic circuits, (can be set to 1/0)
-much smaller than magnetic devices
-large capacity
-more expensive
-aka ‘flash memory’ = non-volatile
Characteristics of SSD
-no moving parts to read/write data
-a collection of circuits wired together to store binary data
-collection of circuits are wired to form a grid
Physical characteristics of SSD
-fast read/write speed > still slower than RAM
-durable
-silent when running
-requires less power than the other devices
Advantages of SSD:
-fast = read speeds up to 550MB per second
-lightweight = typically much smaller than hard drives
-durable = don’t suffer mechanical faults
-low power consumption
-silent
Disadvantages of SSD
-expensive per MB
-typically lower capacity than a hard drive
-can be unreliable
Optical storage meaning
- most commonly used to distribute media/software > e.g movies/video games
-uses lasers to read/write data on reflective surfaces
-typically small in capacity
-cheap to produce
Examples: CDs, DVDs, Blu-Ray discs
Advantages of Optical storage
-media is very portable (compared to hard disk)
-inexpensive when less than 10GB is needed
-immune to magnetic fields, while magnetic media can be damaged
Disadvantages of Optical storage
-media isn’t as robust as magnetic/SSD
-can be easily scratched/damaged
-slower to write than other types of media
-slower to access data from, than magnetic/SSD
Magnetic storage meaning
-oldest form of storage (has been in use since 1920s)
-data is stored in a series of polarised dots
-come in large capacity and inexpensive
-e.g tapes
Advantages for magnetic storage
-huge storage capacity (TB)
-cheapest form of storage per GB
-Data can be stored for a long time
Disadvantages of magnetic storage
-magnetic fields can corrupt/damage data
-not as portable = partially larger/ integrated in computer
-mechanical moving parts = can wear out after time
-slower to access data from media using flash tech (SSD)