Primary Storage | Computer for GCSE/IGCSE - Year 11 PDF Download

Primary Storage

• Primary storage is directly accessible by the CPU, encompassing RAM, Cache, and ROM.

The Role of RAM

• RANDOM ACCESS MEMORY (RAM) serves to hold data, instructions, and active software, including parts of the operating system.
• RAM, also known as main memory, operates with faster read/write speeds compared to secondary storage.
• Being volatile, RAM functions as temporary storage, clearing all data upon computer shutdown.
• A computer's performance can be enhanced with larger RAM, allowing quick access to more data.
• Standard desktop computers typically possess RAM capacities ranging from 4GB to 16GB.

The Significance of Cache

• Cache is designed to retain frequently or recently used instructions and data.
• It operates at superior read/write speeds when compared to RAM.
• Cache exists at different levels, with Level 1 situated within the CPU and Levels 2 and 3 on the motherboard.
• Increasing cache size enables the storage of more frequently accessed data, thus enhancing computer performance.
• An excess of cache can lead to reduced data access speeds as the requested data may take longer to locate.
• Similar to RAM, cache is volatile, leading to data loss upon computer shutdown.

• Read-only memory (ROM) serves to retain the computer's boot-up sequence.
  • The boot-up sequence comprises instructions executed when the computer is first powered on.
  • This sequence conducts various checks to verify the functionality of system hardware.
  • Subsequently, it loads the operating system from secondary storage into RAM.
• ROM is non-volatile, ensuring data retention even when the computer is turned off.
• Being read-only, data cannot be written to ROM.

The difference between ROM and RAM