Types of Memory

Question 1

Explain RAM (include the types).

Answer 1

• Random Access Memory
• Temporary, volatile –> must be powered
• Can be changed
• Can be accessed in any order
• Quick –> accessed by CPU
• Types: DRAM, SRAM

Question 2

What are the differences between DRAM and SRAM?

Answer 2

• DRAM used in RAM modules while SRAM used in the cache
• DRAM is pricier
• DRAM is faster
• DRAM requires a refresh signal

Question 3

What happens when too much memory is being asked of RAM?

Answer 3

Theres a thing called virtual memory.

• When too much for RAM
• Marking out sections in secondary storage for CPU
• secondary storage in Operating System –> still volatile
• moves seamlessly through
• Disk thrashing: too much use of this

How it works:
-Basically things that aren’t needed right now is put into virtual memory and what is used that is in the virtual memory (and within the scope of RAM’s responsibilities) gets put into the RAM

Question 4

Explain ROM.

Answer 4

• Read Only Memory
• CPU and can be accessed in any order
• Read only memory: data cant be changed, overwritten, or removed by running program
• Non-volatile: will be kept with no power
• eg. Hardware settings that should not be changed, initial boot up instructions for the computer, basically data that shouldn’t be changed

Question 5

Differences between RAM and ROM

Answer 5

• ROM is read only, while RAM is read and write
• ROM is volatile, while RAM is not
• ROM chips are found on the motherboard, or on printed circuit. Not removable. RAM chips are removable and slotted into sockets on motherboard, easily removed and updated
• ROM used to hold basic computer hardware settings, and in the past BIOS to boot up computer. RAM is used to hold both data and programs (main memory)
• only a few MB usually for ROM and a few GB in RAM

Question 6

Whats Cache?

Answer 6

• prioritising contents to speed up process

- Keep whatever u saw last (eg pics on a website) so can move back easier –> next time aldy there

Question 7

Explain Mechanical Disks

Answer 7

A type is a magnetic hard drive:
Its an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage and one or more rigid rapidly rotating platters coated with magnetic material. Cheap, but slower than RAM or Solid State Drives.

Question 8

Explain Solid State Drives.

Answer 8

A solid-state drive is a solid-state storage device that stores data persistently, typically using flash memory, and functioning as secondary storage

Question 9

How many bits/bytes are these:

- bit
    - Nibble
- byte
- kilobyte
- megabyte
- gigabyte
    - terabyte

Answer 9

• bit: 1 bit
  
  • Nibble: half a byte
  • byte: 8 bits
  • kilobyte: 1000 bytes
  • megabyte: 1,000,000 bytes
  • gigabyte: 1,000,000,000 bytes
    
    • terabyte: 1,000,000,000,000 bytes