Memory and storage

What does Primary storage consist of

ram, rom, cache and registers

what does primary storage hold

data and instructions cpu needs to access while computer runs

What can cpu access from primary storage quicker than secondary storage

data

What does ram hold

operating system, programs and data in use by cpu when computer runs

describe ram

volatile, read and write, large in comparison to rom

what does rom hold

first instructions when computer first turned on (bootstrap)

where may programs in rom be stored in

embedded systems

describe rom

non volatile, read only, small in comparison to ram

when is virtual memory needed

not enough physical ram to store programs

where is virtual memory held

hard disk

how does virtual memory work

programs transferred to virtual memory from ram when not currently being executed, programs transferred back to ram when needed

Why is secondary storage needed

ROM is read only and RAM is volatile

what tasks are secondary storage needed for

storage of programs and data when computer turned off, semi permanent storage of data that can change, backup and archive of data files

what are some types of optical storage

cd-r, dvd-r, blue-ray

what are properties of data and storage

slow to access data, thin, lightweight and portable and low capacity compared to other storage

what are types of magnetic storage

hard disk drive, tape drive

what are properties of magnetic storage

high storage capacity, quick to access data, moving parts (eventually fail)

how does a hard drive perform better

defragmented

what are examples of solid state storage

ssd, memory sticks, flash memory cards

what are properties of solid state storage

medium storage capacity, quick to access data, reliable (no moving parts), no noise, no noise, low power, no need to defragment, limited number of read/write cycles, expensive compared to other storage

what device you should use is based on

capacity, speed, portability, cost, durability, reliability

describe hard disk

high capacity, access data quickly, cheap, can be portable, eventually fail, bulky and shouldn’t be dropped

describe magnetic tape

high capacity, slow access to data, portable but can be damaged if mishandled, cheap

describe optical

slow (not for serial purposes), portable, durable but susceptible to scratches, data can pressed on quickly

describe solid state

reasonable capacity, rugged, reliable but will fail due to limited number of read write cycle, expensive, fast