This key facts covers Quick Reference - Storage Units within Storage Units for GCSE Computer Science. Revise Storage Units in 3.3 Data Representation for GCSE Computer Science with 15 exam-style questions and 18 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 9 of 10 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Quick Reference - Storage Units
The Ladder (Memorize This!):
1 bit = 0 or 1 1 byte = 8 bits 1 KB = 1,024 bytes 1 MB = 1,024 KB 1 GB = 1,024 MB 1 TB = 1,024 GB 1 PB = 1,024 TB
Real-World Sizes:
- 1 KB: Short email, small text file
- 1 MB: High-quality photo, 1 minute of music
- 1 GB: HD movie (compressed), ~300 photos
- 1 TB: 250 movies, 250,000 songs, your entire computer backup
Common File Sizes:
- Text document: 50-500 KB
- Photo (phone): 2-5 MB
- Photo (DSLR): 5-20 MB
- Song (MP3): 3-5 MB
- HD movie: 4-8 GB
- PC game: 20-100 GB
Practice questions for Storage Units
How many bits make up one nibble?
Explain what is meant by colour depth and describe how increasing the colour depth affects both the image quality and the file size.