Memory & StorageKey Facts
Quick Reference - Secondary Storage
Part of Secondary Storage — GCSE Computer Science
This key facts covers Quick Reference - Secondary Storage within Secondary Storage for GCSE Computer Science. Revise Secondary Storage in Memory & Storage for GCSE Computer Science with 15 exam-style questions and 18 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 10 of 10 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 10
Practice
15 questions
Recall
18 flashcards
Quick Reference - Secondary Storage
Speed Ranking (Fastest to Slowest):
- SSD: 500-7000 MB/s (NVMe can reach 7 GB/s!)
- HDD: 100-200 MB/s
- Optical: 1-8 MB/s (50-200x slower than HDD)
Cost Ranking (Cheapest to Most Expensive per GB):
- HDD: £0.02-0.03 per GB
- Optical: ~£0.01 per GB (but very low total capacity)
- SSD: £0.10-0.15 per GB
Capacity Ranking (Highest to Lowest):
- HDD: 1-20 TB (consumer), up to 100TB+ (enterprise)
- SSD: 256 GB - 8 TB (consumer)
- Optical: 700 MB (CD) to 100 GB (Blu-ray triple-layer)
One-Sentence Summary:
- HDD: Cheap and huge but slow and fragile
- SSD: Fast and durable but expensive
- Optical: Portable and cheap per disc but very slow and low capacity