1.2 Memory

Question 1

What are the two types of memory?

Answer 1

• Main memory

* Secondary storage

Question 2

Which memory can be directly accessed by the CPU?

Answer 2

Main memory

Question 3

True or False? Main memory can only hold one program at a time

Answer 3

False - it can hold more than one making it quicker for the CPU to swap between tasks.

Question 4

What is secondary storage used for?

Answer 4

Secondary storage is used for holding large amounts of data and programs long-term, but can only be accessed relatively slowly.

Question 5

What is volatile memory?

Answer 5

Volatile memory is memory that loses its data once power to the memory chip is switched off or interrupted.

Question 6

What is RAM used for?

Answer 6

• RAM is used as main memory

* It is used as a temporary store for program instructions and data

Question 7

What will happen if RAM loses its power?

Answer 7

It will lose any data its holding because it is. volatile

Question 8

Why is it called ‘Random Access Memory’?

Answer 8

Data or instructions can be accessed in any order (non sequentially)

Question 9

What are the two types of RAM?

Answer 9

• DRAM (Dynamic)

* SRAM (Static)

Question 10

What type of RAM is found in a RAM module and why?

Answer 10

• DRAM

* It is relatively inexspenive

Question 11

What type of RAM is used for the cache and why?

Answer 11

• SRAM

* It is much faster to access than DRAM

Question 12

Which type of RAM requires a refresh signal to keep its data intact?

Answer 12

DRAM

Question 13

How much RAM does a budget laptop include?

Answer 13

Around 4GB

Question 14

Use of which application could require up to 32GB of RAM?

Answer 14

A professional video editing application.

Question 15

What does ROM stand for?

Answer 15

Read Only Memory

Question 16

What are the two differences between RAM and ROM?

Answer 16

• ROM is read only (cannot be changed) whereas RAM is read/write memory (contents can be altered).
• ROM is non volatile (meaning it keeps its data when there is no power supply) whereas RAM is volatile.

Question 17

What is ROM used to hold?

Answer 17

• Basic computer hardware settings

* In the past it held the BIOS to boot up the computer

Question 18

Why are ROM chips not removable?

Answer 18

They are soldered into the motherboard.

Question 19

What makes RAM chips easy to remove and update?

Answer 19

They are located in removable memory modules that are slotted into sockets on the motherboard.

Question 20

What is the typical memory of ROM?

Answer 20

A few megabytes

Question 21

On what type of memory is BIOS now stored and why?

Answer 21

Flash memory so that changes to the instructions can be made (flash memory is non volatile and read/write)

Question 22

What happens when RAM gets too full?

Answer 22

The computer operating system can help out by temporarily marking sections of secondary storage for the CPU to store data on.

These sections are called virtual memory.

Question 23

Does the CPU directly access data held in virtual memory?

Answer 23

• No - it asks the operating system to first load it into RAM, which is quick to access.
• Less-used data is moved from RAM to virtual memory to make room for it.

Question 24

What is Disk Thrashing? (3)

Answer 24

• As main memory fills up, then more and more pages need to be swapped in and out of virtual memory.
• This swapping leads to a very high rate of hard disk access
• Leading to wear and tear on the disk and a slow-down in overall performance.

Question 25

What are two solutions to Disk Thrashing?

Answer 25

• Fitting more RAM

* Reducing the number of applications being used at the same time