This deep dive covers Deep Dive: Why 1024 Instead of 1000? 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 2 of 10 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Deep Dive: Why 1024 Instead of 1000?
Computers work in binary (base 2), so everything is powers of 2. The closest power of 2 to 1,000 is 210 = 1,024. This creates an interesting situation:
- Binary system (IEC standard): 1 KiB = 1,024 bytes (used by programmers, RAM specs)
- Decimal system (SI standard): 1 KB = 1,000 bytes (used by hard drive manufacturers, marketing)
This is why your "1 TB" hard drive shows as only 931 GB in Windows - the manufacturer used decimal (1,000^4 bytes) but Windows uses binary (1,024^4 bytes). You didn't lose 69 GB - it's just a measurement difference!
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.