Secondary Storage (Cambridge (CIE) O Level Computer Science)
Revision Note
Author
James WoodhouseExpertise
Computer Science
Secondary Storage
Storage devices are non-volatile secondary storage, that retain digital data within a computer system
They provide a means of storing, accessing, and retrieving data, which can include software applications, documents, images, videos, and more
There are 3 types of storage:
Magnetic
Solid State
Optical
Computer systems need both primary and secondary storage to operate
Both types of storage play a crucial role in the operation of a computer system
A quick comparison of primary and secondary storage shows:
Primary | Secondary |
|---|---|
Volatile (with the exception of ROM) | Non-volatile |
Small capacity | Large capacity |
Why do you need secondary storage?
A computer needs secondary storage for long term storage of programs and data that are currently not in use
Secondary storage is needed as ROM is read only and RAM is volatile
Secondary storage holds the programs and data whilst the computer is turned off (non-volatile)
Performance of secondary storage is slower than primary storage but capacity is much higher which makes it perfect for backup & archive of data files
What are the characteristics of secondary storage?
Capacity - What is the maximum amount of data that can be stored?
Speed - How fast can data be read from and written to? (R/W)
Cost - How much does it cost?
Portability - How easy is it to move around? What is the physical size? Weight?
Durability - How robust is the storage?
Reliability - What is the probability that the device will consistently perform its function?
Worked Example
A games console has secondary storage.
State, using an example, why the games console needs secondary storage [2]
How to answer this question
They keyword is 'why', why does a games console need secondary storage? give an example, do not just describe what secondary storage is!
Answer
To store data once the power is turned off / permanently // for non-volatile storage
Examples could include:
Storing games
Save games
User data/profiles
Downloaded content/applications/updates
Magnetic Storage
What is magnetic storage?
Magnetic storage is a type of non-volatile media that uses magnets (polarity) to store binary 0s and 1s
Advantages | Disadvantages |
|---|---|
Capacity - High storage | Durability - Moving parts can get damaged if dropped |
Cost - Low per gigabyte | Portability - Heavy & bulky making them less convenient for transport |
Speed - Moderate read/write access | Reliability - Prone to mechanical failure |
| Noise - Loud (spinning disks) |
Solid State Storage
What is solid state storage?
Solid state storage is a type of non-volatile media that uses electronic circuits to store binary 0s and 1s
Advantages | Disadvantages |
|---|---|
Capacity - Medium/high storage | Cost - Very high per gigabyte |
Speed - Very fast read/write access | Reliability - Limited read/write cycles |
Durability - No moving parts |
|
Portability - Small and no moving parts |
|
Noise - Silent |
|
Optical Storage
What is optical storage?
Optical storage is a type of non-volatile media that uses lasers to burn the surface of a disk, creating pits and lands suitable for storing binary 0s and 1s
Advantages | Disadvantages |
|---|---|
Cost - Very low per gigabyte | Capacity - Very low |
Durability - No moving parts | Speed - Very slow read/write access |
Portability - Small and no moving parts | Reliability - Prone to scratches |
Noise - Silent |
|
Worked Example
Zarmeen has purchased a new tablet computer. The tablet has an internal secondary storage device.
The storage device is a solid state device.
Give three benefits of the tablet having a solid state device instead of a magnetic device [3]
Give two drawbacks of the tablet having a solid state device instead of a magnetic device [2]
Answers
Benefits
Faster access / read/write speeds
Smaller in physical size
More durable // no moving parts
Drawbacks
More expensive (per gigabyte)
Smaller capacity (usually)
Limited number of read/write cycles
Guidance
Portable is not enough on it's own
No moving parts is not enough on it's own
You've read 0 of your 0 free revision notes
Get unlimited access
to absolutely everything:
- Downloadable PDFs
- Unlimited Revision Notes
- Topic Questions
- Past Papers
- Model Answers
- Videos (Maths and Science)
Did this page help you?