Unit 1.3 Storage Lesson 1: Storage Devices

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?

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

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?

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

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.

Types of Storage Optical Magnetic Solid State

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

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

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

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

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

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

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

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?

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.

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?

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

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

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

Key Words Storage Characteristic Estimate Overheads

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.

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?

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?

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

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

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

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