Secondary Storage Flashcards
Primary Storage
memory areas that the CPU can access very quickly
e.g. CPU Registers, cache, ROM, RAM
Secondary Storage
non - volatile
where all data is stored when not in use
e.g Magnetic hard disk drives, SSD, CDs and SDs cards
Read/write speeds are slower than primary storage
Solid State Drives
Storage devices with no moving parts
use a type of flash memory (type of non-volatile memory)
Other types of flash storage
USB pen drives + memory cards -> slower than SSDs/shorter read-write life + used to expand storage capacity of small devices e.g. cameras, smartphones
Have very high capacity
Optical Discs
things like CDs, DVDs, Blu-Ray discs
CD capacity
700 MB of data
DVDs
4.7 GB of data
Blu - Rays
25 GB
3 types of Optical discs
read-only (e.g. CD-ROM, DVD-ROM, hBD-ROM)
write-once(e.g. CD-R, DVD-R, BD-R)
rewritable(e.g. CD-RW, DVD-RW, BD-RW)
Advantages of Optical Discs
Cheap
portable
not damaged by water and shocks
Disadvantages of Optical Discs
Easily Scratched Use is declining -> unnecessary Slow read/write speeds Low capacity Poor reliability
Magnetic Tapes
used for large organisations in archive libraries to store huge amounts of data
Is read/written sequentially (read/written from beginning to end)-> tape is very slow when finding specific data
