1. Unit 1.3 Storage Lesson 1: Storage Devices

2. Big Picture
What do you store on your phones? On your computers? Tablets? Why do we need storage devices? What could computers do without storage devices?

3. Learning Objectives
Identify the need for and purpose of secondary storage
Identify common types of storage
Match storage devices to their type of storage
Explain the characteristics of common types of storage

4. Engagement Activity
In pairs, list all the different storage devices that you use (or have used).
Extensions: What did you use them for? What type of data did you store?

5. Key Words Secondary storage Optical Magnetic Solid State Cloud Storage
Durability
Reliability
Portability
Capacity
Speed

6. What is Secondary Storage?
Long term storage of data, files, software, OS.
Why do we need to store these things?
To access it again later
To use software
To interact with the computer
What would happen without secondary storage?
Software would need to be installed each time we use it
You couldn’t save any files, data, images, videos etc.

7. Types of Storage
Optical
Magnetic
Solid State

8. Optical A laser light creates marks in a pattern on the disk
A laser light detects where the marks are and translates this into a readable format

9. Magnetic
Read/write move across the medium and change how magnetised that part of the medium is
E.g. one level of magnetism will be a 1, a second will be a 0

10. Solid State This is made of microchips (switches)
The state of the switches determine if a 1, or 0 is stored

11. Activity 1
In pairs, complete the table, identifying if each storage device is magnetic, optical or solid state.
Extension – discuss the questions at the bottom of the worksheet

12. Activity 1 - Answer Device Magnetic Optical Solid state
Hard Disk Drive 
Solid State Drive
Blu ray
DVD ROM
SD Card
USB Memory Stick
CD ROM
Tape Drives

13. Data capacity
Research the size of each of these units of storage and put them in order from lowest to highest: GB KB
Byte MB
Nibble
Bit

14. Characteristics of Storage Devices
What do we mean by “characteristics”?
A characteristic is a feature, attribute or distinguishing trait

15. Characteristics of Storage Devices
Capacity
how much data can it store?
Speed
how fast can it access the data?
Portability
how easy is it to move it from one place to another
Durability
how well does it last e.g. if it is dropped
Reliability
how consistently does it perform
Cost
how much does it cost per KB, MB or GB?

16. Characteristics of Storage Devices
Type of device
Capacity
Speed
Portability
Durability
Reliability
Cost
Optical 3 2
Magnetic 1
Solid State
Based on your research and knowledge – is 1 best or 3 best?
The table has ‘1’ as being the best – ‘3’ is least good.
Disclaimer: these rankings are ‘in general’, there are likely to be many individual devices that do not quite fit this pattern.

17. Plenary Questions What is secondary storage?
Why do we need secondary storage?
What are the 3 types of storage?
What type of storage is a USB memory stick?
What type of storage is a CDROM?
What type of storage is a HDD?
What type of storage is the fastest to read data from?
What type of storage is the most expensive per GB?
What type of storage is the most reliable?
What type of storage is the least durable?

18. Big Picture
How do you decide which storage device to buy? Do you own one? Why did you choose that one?

19. Learning Objectives
Be able to recommend a storage device for a situation
Estimate data capacity requirements for different file types

20. Engagement Activity
A CD ROM is better than a USB Memory Stick.

21. Key Words
Storage
Characteristic
Estimate
Overheads

22. Recommending a storage device
What characteristics can you remember from last lesson?
Capacity
Speed
Portability
Durability
Reliability
Cost
Use these to decide which type to recommend...
...and why. The why is as important as the what.

23. Scenario 1
A graphics designer needs to store their creations (images, sound and video). They work mainly from home, but like to take their work to events and meetings.
What characteristics do they need from the storage device?
Large capacity
Portability
Durability
Reliability
What do you recommend? Why?

24. Scenario 2
The Managing Director of a small accountancy firm stores data about the company’s clients and their accounts. The Managing Director only works at the office.
What characteristics do they need from the storage device?
Small capacity
Reliability
Fast access
What do you recommend? Why?

25. Activity 1 For each of the scenarios on the worksheet:
Identify the most appropriate type of storage
Justify (explain) your choice

26. Activity 1 – Answers
Scenario
Type of Storage
Justification
A student needs to bring their homework into school
 Solid state
e.g.
Portable – for carrying to and from school
Durable – can be knocked around in bags and not break
Fairly reliable – unlikely to get scratch like optical
A media student needs to store a video they have made to distribute to their friends
Optical/Solid state 
 e.g. (for optical)
Capacity - Only 1 video needs saving and this will be sufficient
Portability – can be transported, so given to other people
Durability – is poor, but it does not need to be moved a lot, only once to another person
Cost – this is low and as the device is to be given away this is more beneficial
A software developer has created a trial version of their software that will be given away in magazine
 Optical
Cost – to be given away, so low cost needed
Portability – small enough to be put in magazine, can be moved
Durability – will need protecting in magazine
Capacity – sufficient for software
A school needs to back-up its data every evening
 Magnetic
e.g. (for magnetic) Tape Drive or Large HDDs
Capacity – large so can hold all types of data
Speed – relatively fast, so backup will not take a long time
Portability – does not need to be moved
Reliability – fairly reliable type so backup is unlikely to be lost
Cost – low per GB

27. Activity 1 – Answers
A large corporation needs to store data about its customers, stock and orders
Magnetic/SS 
 e.g. (for magnetic)
Capacity – large so can hold all the data
Speed – relatively fast, so data can be found and retrieved quickly
Portability – does not need to be moved
Reliability – fairly reliable to data will not be lost
Cost – low per GB and a large capacity will be needed
A web server needs to store a multimedia website for web-users to access
 Magnetic/SS
e.g. (for magnetic)
Capacity – large so can hold range of multimedia
Speed – relatively fast, so server requests will be within a reasonable time
Reliability – fairly reliable type so ca be accessed many times
Cost – low per GB

28. OCR Resources: the small print OCR’s resources are provided to support the teaching of OCR specifications, but in no way constitute an endorsed teaching method that is required by the Board, and the decision to use them lies with the individual teacher. Whilst every effort is made to ensure the accuracy of the content, OCR cannot be held responsible for any errors or omissions within these resources. © OCR This resource may be freely copied and distributed, as long as the OCR logo and this message remain intact and OCR is acknowledged as the originator of this work.
OCR acknowledges the use of the following content: n/a
Please get in touch if you want to discuss the accessibility of resources we offer to support delivery of our qualifications: