This key facts covers Quick Reference - Key Points within RAM and ROM for GCSE Computer Science. Revise RAM and ROM in 3.4 Computer Systems for GCSE Computer Science with 16 exam-style questions and 16 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 10 of 11 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Quick Reference - Key Points
RAM Summary:
- Volatile - loses data when power off
- Read/write - fast in both directions
- Stores: running programs, open files, OS, active data
- Temporary - cleared on shutdown
- Larger capacity (4GB-32GB typical)
ROM Summary:
- Non-volatile - keeps data without power
- Read-only - cannot easily change (or very slow write)
- Stores: BIOS/UEFI, boot instructions, firmware
- Permanent - rarely changes (firmware updates only)
- Smaller capacity (few MB typical)
Memory Hierarchy (Fastest to Slowest):
- CPU Registers: Tiny (bytes), inside CPU, fastest
- CPU Cache (L1/L2/L3): Small (KB-MB), on CPU, very fast
- RAM: Medium (GB), main memory, fast
- ROM: Small (MB), firmware storage, moderate speed
- SSD: Large (GB-TB), permanent storage, slower than RAM
- HDD: Largest (TB), permanent storage, slowest
Practice questions for RAM and ROM
Which of the following best describes RAM?
Explain why the BIOS must be stored in ROM rather than RAM.
Quick recall flashcards
What does ROM stand for?
Read Only Memory
What does RAM stand for?
Random Access Memory