Memory Flashcards
what are the three tiers of storage?
primary storage, secondary storage and tertiary storage
what’s primary storage?
memory areas that the CPU can access very quickly. Has the fastest read/write speeds and is mostly volatile.
what’s secondary storage?
non-volatile, where all data are stored when not in use. It includes magnetic hard disk drives, solid state drives, CDs and SD cards. Read/write speeds are much slower compared to primary storage.
what’s tertiary storage?
non-volatile and used for storing data more long term - mainly used for archives and back-ups of massive amounts of data.
what are hard disk drives?
the traditional internal storage in PCs and laptops
what’s a hard disk drive made of?
a stack of magnetised metal disks spinning at a rate between 5400 and 15000 rpm (revolutions per minute)
where is data stored?
magnetically in small areas called sectors within circular tracks. Read/write heads on a moving arm are used to access sectors on the disks.
what are portable HDDs popular for?
backing up and transporting large amounts of data
properties of HDD
long lasting and reliable
what are Solid State Drives (SSDs)?
storage drives with no moving parts. Most use flash memory. Used for internal storage.
what can SSD give different compared to HDD?
quicker times for booting up and opening programs and files
what do hybrid drives use?
solid state storage for the OS and programs, and a hard disk for data
like HDDs, what can portable SSDa be used for?
backing up and transporting data
other types of flash storage
pen dries and memory cards (e.g.SD cards)
what are USB pen drives and memory cards?
- flash based, solid state storage
- slower than SSDs + have shorter read/write life
- used to expand storage capacity of small devices (cameras, smarphones).
