This key facts covers Bits vs Bytes - The Confusion! 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 7 of 10 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Bits vs Bytes - The Confusion!
Why Two Different Units?
- Bits (b): Used for data TRANSMISSION (network speeds, download speeds)
- Bytes (B): Used for data STORAGE (file sizes, disk capacity)
The 8:1 Rule:
Since 1 byte = 8 bits, you divide by 8 to convert:
- 100 Mbps internet: 100 ÷ 8 = 12.5 MB/s actual download speed
- 1 Gbps fiber: 1000 ÷ 8 = 125 MB/s actual download speed
Example Calculation:
You have 50 Mbps internet. How long to download a 500 MB file?
Step 1: Convert Mbps to MB/s: 50 ÷ 8 = 6.25 MB/s
Step 2: Divide file size by speed: 500 MB ÷ 6.25 MB/s = 80 seconds
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.