Memory And Storage (part 1) Flashcards
What are the different components of the CPU?
- Arithmetic logic unit
- Control unit
- Cache
- Registers
What does volatile mean?
When the power is turned off all data is lost
Give four examples of primary storage
- RAM
- ROM
- Registers
- Cache
What is secondary storage?
Long term, non volatile storage for data and files
What is tertiary storage?
Storage for backing up and archiving large amounts of data
Name 3 features of primary storage
- Volatile (except ROM)
- Usually has small storage capacity
- Fast access speeds
Name 3 features of secondary storage
- Non-volatile
- Usually much larger storage than primary
- Slow access speeds
What does RAM stand for?
Random Access Memory
What is the purpose of RAM?
- Temporary storage for instructions and data for programs being executed by the processor (transferred from the HDD)
- For reading and writing data
- That holds the OS when the computer is running
Why are instructions transferred from the hard disk to RAM?
Too slow to execute instructions from hard disk
Is RAM volatile?
Yes
What types of storage is RAM?
Primary Storage
What does ROM stand for?
Read Only Memory
What is the bootstrap?
Startup instructions to load the OS
Why are instructions transferred from ROM to RAM?
Too slow to execute instructions from ROM
What does BIOS stand for?
Basic Input Output Settings
What is firmware?
Software installed on the ROM
What is ROM?
Small piece of read only memory that can only be written to once, holds the bootstrap
What type of storage is ROM?
Primary Storage
Is ROM volatile?
No
What is virtual memory?
Part of the hard disk reserved for memory as if it was RAM
When is virtual memory needed?
When RAM is full
Name 2 disadvantages of using virtual memory
- Slower performance
- Causes disk thrashing
What causes disk thrashing?
Swapping too many things between RAM and virtual memory
What needs to happen to data when a computer is turned off?
Needs to be transferred to secondary storage
Why is virtual memory slow?
When an instruction is fetched, it will be checked for in the cache, then RAM, then virtual memory. The program or data is then swapped into RAM then fetched and brought back to the CPU
Can you save files into ROM? Why?
No, since it is read only
Can you save files into RAM? Why?
No, since it is volatile
Why is secondary storage needed?
It is read/write and non-volatile and therefore can be used to save files
What are the different types of secondary storage?
- Magnetic
- Solid state
- Optical
How can you store data with magnetic storage?
Using magnetism
How can you store data with solid state storage?
Using semiconductor chips
How can you store data with optical storage?
Physically burning the surface of the disc, creating pits and lands
What does HDD stand for?
Hard Disk Drive
Which type of secondary storage is the largest per GB?
Magnetic
How much data can a compact disc store?
700MB
What does CD stand for?
Compact Disc
What does SSD stand for?
Solid State Drive
What is a drive?
A device that reads and writes data from the secondary storage
What is storage media?
What data is stored on
Name some examples of optical storage
- Compact disc (CD-R + CD-RW)
- DVD (DVD-R + DVD-RW)
- Blu-ray
Why can DVDs hold more data than CDs?
The pits and lands are smaller and closer together
What are the advantages of optical storage?
- Cheap
- Lightweight
- Portable
What are the negatives of optical storage?
- Slow to access data as data is read in a spiral
- Can be read only due to it being burnt
- Low storage capacity
Name some examples of magnetic storage
- HDD
- DAT Tape
What are the advantages of magnetic storage?
- Cheap
- Large storage capacity
What are the disadvantages of magnetic storage?
- Very slow
- Fragile
- Has moving parts which will eventually fail
Name some examples of solid state storage
- SSD
- Memory stick
- Flash drive
What are the advantages of solid state storage?
- Quick to access data
- No noise
- Low power
- Reliable
What are the disadvantages of solid state storage?
- Limited number of read/write cycles
- Expensive
What is flash memory?
A type of solid state memory with no moving parts. It uses electronics instead of mechanics
