Secondary Storage Flashcards
When may virtual memory be needed?
When too many applications are open at once, or if a memory intensive application is being used.
What is virtual memory?
Data that is not frequently used moved to a location on secondary storage.
What is secondary storage?
Where all data is stored when not in use. It is also non-volatile.
What does HDD stand for?
Hard Disk Drive
What is a HDD made up of?
Magnetised metal disks spinning at 5400 to 15000 rpm
How is data on a HDD stored?
Magnetically in small areas known as sectors within circular tracks.
How is data read/written to a HDD?
With a read/write head on a moving arm to access sectors on the disks.
What does SSD stand for?
Solid State Drive
What do most SSDs use?
A type of flash memory
What are some examples of flash storage?
USB pen drives, memory cards
What are the advantages of HDDs over SSDs?
Cheaper, higher capacity, longer read/write life
What are the advantages of SSDs over HDDs?
Faster, don’t need defragmenting, more shock-proof, silent
What are some examples of optical disks?
CDs, DVDs and Blu-Ray
What is the capacity of a CD?
700MB
What is the capacity of a DVD?
4.7GB