5.2 - Data Storage Flashcards
3 groups of memory storage devices
Primary memory
Secondary storage
Offline storage
Examples of internal secondary storage (2)
HDD (Hard Disk Drive)
SSD (Solid State Drive)
Examples of external secondary storage (5)
DVD
CD
DVD - RAM
Blu-ray disk
USB
Difference between primary memory and secondary storage (5)
primary memory directly addressable by CPU while secondary storage not
Secondary storage is all non-volatile
secondary storage can be external or internal to computer
Primary storage faster to access than secondary storage
primary stores less data than secondary
Function of primary memory
allows CPU to access applications/services temporarily stored in memory locations
Can RAM be written to
yes
Can RAM be read from
yes
Function of RAM (4)
store data
store files
store part of application currently in use
store part of operating system currently in use
Is RAM temporary or permanent
temporary - data can be changed by user or computer
Is RAM volatile or non-volatile
volatile - memory contents lost when powering off computer
What are the 2 types of RAM technology (2)
DRAM (Dynamic RAM)
SRAM (Static RAM)
Which RAM does Cache use
SRAM
How does SRAM work
uses flip-flops which hold each bit of memory
SRAM and DRAM differences (6)
SRAM more expensive
SRAM more power
DRAM for main memory while SRAM for cache
SRAM faster
DRAM stores more bits per chip
DRAM needs to be recharged to maintain data while SRAM holds data as long as there is power
ROM features (4)
non-volatile - data not lost once computer powered off
ROM is permanent - cannot be changed or written to
contents can only be read
often used to store instructions a computer needs to access when powering up
When is ROM used
BIOS (basic input and output system)
Differences between RAM and ROM (4)
RAM is a temporary memory device while ROM is a permanent memory device
RAM is volatile while ROM is non-volatile
RAM can be written to and read from but ROM cannot be altered
RAM used to store data currently in use while ROM stores data needed to start up
3 types of technology for secondary (and off-line) storage (3)
magnetic
solid state
optical
What technology does HDD use
magnetic
Disadvantages of HDD (2)
hard disk can have slow data access when compared to RAM
can have latency - time delay
Do SSDs have moving parts
no
Benefits of SSDs over HDDs (5)
no moving parts - more reliable/less damage
lighter
thinner
data is faster than HDD
lower power consumption
Drawbacks of SSD (2)
does not last long
is usually not used in servers
Benefits of memory sticks (2)
small for transferring files between computers
can be used as small back-up devices
