Computer Chapter 6.4 Memory and Storage

• ICT
• Secondary Education

6.4 Memory and Storage

Primary Memory

Primary memory is the computer’s main memory, which is directly accessible by the CPU and often much faster than secondary storage.

Examples of primary memory / storage:

Random Access Memory (RAM) – solid state

Read Only Memory (ROM) – solid state

RAM

ROM

What is RAM?

RAM is a computer’s primary memory. It is a very fast solid state storage medium that is directly accessible by the CPU

What is RAM?

Any open programs or files on a computer are temporarily stored in RAM whilst being used.

What is RAM?

Being volatile, any data stored in RAM will be lost when power is removed. This makes RAM totally unsuitable for the long term permanent storage of data – that is the role of a HDD or SSD instead.

What is RAM?

Data is copied from secondary storage (HDD, SSD) to RAM as and when it is needed. This is because using a HDD as the primary memory would cause a computer to perform much slower (a HDD or SSD is not directly accessible to the CPU, and isn’t as fast as RAM).

What is RAM?

RAM is a relatively expensive storage device and typical capacities are measured in Gigabytes (GB).

Computers operating with a capacity of RAM above the recommended minimum will benefit from better performance and multitasking.

RAM is volatile.
What is meant by volatile?

Is RAM expensive?

1. Yes
2. No

Benefits of RAM

• Directly accessible to the CPU, making processing data faster
• Fast solid state storage, making processing data faster

Drawbacks of RAM

• Relatively expensive memory
• Volatile – any data stored in RAM is lost when power is removed

There are two types of RAM (SRAM and DRAM)

Research  what is SRAM and DRAM?

Write 3-5 points for each in your journal.

(20 Mins)

Static RAM (SRAM)

• Data on SRAM does not require refreshing.
• However, the technology is bulkier meaning less memory per chip.
• More expensive than DRAM
• Much faster than DRAM
• Consumes less power
• Commonly used in cache memory

Dynamic RAM (DRAM)

• The most common type of RAM in use.
• The data needs to be continually refreshed otherwise it fades away.
• Continually refreshing the data takes time and reduces performance speeds.