← IGCSE Computer Science Paper 1

Why secondary storage is needed

Permanent, non-volatile storage with a much larger capacity than RAM. It keeps files, programs and the OS safe when the power is off, because RAM is volatile and too small.

Part of: IGCSE Computer Science 0478 — 3.3 Data Storage — Module 8

Understanding Why secondary storage is needed in IGCSE Computer Science Paper 1

What it does: Non-volatile means the data stays when the power is off, which is why secondary storage holds files, programs and the OS. The capacity claim is the wrong way round: secondary storage is larger, and it is the permanent store.

Common mistakes: An SSD is secondary storage, which is non-volatile. Its data is kept when the power is off, so the line should be SSD data ← KEPT. Secondary storage has a much larger capacity than RAM. A value of 4 is smaller than the RAM value of 8, so it should be a larger number such as 512.

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This module's key terms are also in a printable crossword (Modules 304–313) and word search (Modules 304–324).

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Learning
Duo
A student switches off the computer. What happens to a file that was only in RAM?
It is kept, because RAM is permanentIt is lost, because RAM is volatile
Matches
Save my homework in RAM so it is kept forever
↓
RAM is volatile, so the homework would be lost when the power goes off. It should be saved to secondary storage.
Applying
Meanings
Term
secondary storage
Meaning
Permanent, non-volatile storage with a much larger capacity than RAM. It keeps files, programs and the OS safe when the power is off, because RAM is volatile and too small.
Practice
DECLARE essay : STRING
Testing
Gaps
RAM is , so it loses data
Check Answer
Spots
2 RAM data ← LOST
3 SSD data ← LOST

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Quick Questions

1. A student switches off the computer. What happens to a file that was only in RAM?
A. It is lost, because RAM is volatile ✓
B. It is kept, because RAM is permanent
RAM is volatile, so its contents are lost when the power is off. Files must be saved to secondary storage to keep them.
2. Which statement explains why secondary storage is needed?
A. It keeps data when the power is off ✓
B. It makes the CPU run faster than RAM
Secondary storage is non-volatile, so data survives power-off. Its main job is permanent storage, not being faster than RAM.
3. Which has the much larger capacity in a typical computer?
A. RAM
B. Secondary storage, such as an SSD or HDD ✓
Secondary storage is usually hundreds of GB or TB, while RAM is usually only a few GB to a few tens of GB. So it can hold many more files and programs.
4. Where is a saved photo kept when you are not using it?
A. In RAM
B. In secondary storage ✓
Saved files stay in secondary storage. They are only copied into RAM while the computer is working on them.
5. Which is a reason RAM cannot be used for permanent storage?
A. It is volatile and has limited size ✓
B. It is non-volatile and has unlimited size
RAM loses its data when power is off and is smaller than secondary storage, so it is unsuitable for permanent storage.

Match the Pairs

Secondary storage → Permanent storage that keeps files, programs and the OS when the power is switched off
RAM = volatile → Its contents are lost when power is turned off, so it cannot keep files permanently
Data survives power-off, so files can be kept long term → Secondary storage = non-volatile
Secondary storage has a much larger capacity than RAM → RAM: 8 GB, SSD: 1000 GB
Save my homework in RAM so it is kept forever → RAM is volatile, so the homework would be lost when the power goes off. It should be saved to secondary storage.
RAM is bigger than secondary storage, so it stores all the files → Secondary storage usually has a much larger capacity than RAM, and RAM is volatile, so files are stored on secondary storage.

Key Term

secondary storage
Permanent, non-volatile storage with a much larger capacity than RAM. It keeps files, programs and the OS safe when the power is off, because RAM is volatile and too small.

Fill in the Blanks

1. RAM is volatile, so it loses data
Hint: Type the word for memory that loses its data when the power is off.
2. Secondary storage is non-volatile
Hint: Type the term for memory that keeps data without power. It is the opposite of volatile.
3. IF secondaryCapacity > ramCapacity THEN
Hint: Type the comparison operator that shows secondary storage is larger than RAM.
4. Kept at power off: secondary storage
Hint: Type the kind of storage that keeps files, programs and the OS when the computer is switched off.
5. Programs are loaded from storage into RAM
Hint: Type the primary memory that holds running programs and data while the computer is on.

Spot the Error

Question 1
A IF power = OFF THEN
B RAM data ← LOST
C SSD data ← LOST
D ENDIF
Line C — An SSD is secondary storage, which is non-volatile. Its data is kept when the power is off, so the line should be SSD data ← KEPT.
Question 2
A ram ← 8
B storage ← 4
C IF storage > ram THEN
D OUTPUT "Storage is larger"
E ENDIF
Line B — Secondary storage has a much larger capacity than RAM. A value of 4 is smaller than the RAM value of 8, so it should be a larger number such as 512.
Question 3
A file ← "report.docx"
B SAVE file TO RAM
C POWER OFF
D POWER ON
E OPEN file FROM SSD
Line B — RAM is volatile, so a file saved only there is lost when the power goes off. The file must be saved to secondary storage such as the SSD.
Question 4
A POWER ON
B READ OS FROM SSD
C MOVE OS INTO RAM
D RUN OS
Line C — The OS is copied into RAM to run, so a permanent copy stays on secondary storage. Moving it would leave it only in volatile RAM, and it would be lost at power-off. It should be COPY.
Question 5
A Primary: RAM
B Volatile: NO
C Size: small (GBs)
D Secondary: SSD
E Volatile: NO
Line B — RAM is primary storage and is volatile, so its data is lost when the power is off. The line should say Volatile: YES.

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