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3.1 Storage devices



Unit 3.1 Storage devices
Unit 3.2 Processing devices
Unit 3.3 Basic troubleshooting

image By the end of this chapter, you will be able to:

  • Describe the difference between primary and secondary storage
  • Discuss online storage
  • List the best storage media for backups and archiving
  • Describe the role and function of various internal computing components, such as the motherboard, CPU, RAM and ROM
  • Interpret advertisements for storage media and computers
  • Do basic troubleshooting on input, output, storage and processing devices


In this section, you will get more detail about the purpose of storage, what the difference is between primary and secondary storage, why computers need storage and what online storage is. You will be introduced to the storage devices that do the processing in a computer, such as the motherboard, random-access memory (RAM), read-only memory (ROM) and central processing unit (CPU) and what their functions are.

 3.1   Storage devices

Storage media have come such a long way since the early days of computing, and the size of data has grown so much that it is impossible to imagine that all it took to get humans to the moon was about 600 MB of data.

Something to know

One gigabyte (GB) is equal to 1 024 megabytes (MB), and one terabyte (TB) is equal to 1 024 GB.


Primary storage is also called the main or internal memory of the computer. This storage is accessed directly by the CPU and is where the main instructions for the computer’s operations are stored. The CPU can access these instructions and execute them as they are needed.

Primary storage is most often the RAM and the ROM, which will be discussed later in this chapter. The main function of the primary storage devices is to hold data for a short period of time while the computer is running and power is going to the devices. This data is removed once the power is stopped (like when the computer is shut down).


Secondary storage is also called external, secondary or auxiliary memory. This type of storage holds data for the long term. Data stored on secondary storage devices can only be removed by deleting it. Secondary memory is where the operating system, hardware drivers and data created by the user is kept and stored permanently.

This means that, in the case of power failures, secondary storage will preserve the information that is saved to it, even if the power to the computer is lost, while the data on the primary storage devices will be lost.

The most common example of secondary storage is the hard drive inside a computer. Other examples include solid-state drives (SSDs), USB flash drives and secure digital (SD) cards.

Table 3.1: Comparison: Memory versus storage



One purpose of storage devices is to back up or archive your important data. In the business world, there is a need to store data permanently and in a way that does not get destroyed, corrupted or damaged easily. Different types of storage media can be used for backing up or archiving.

Backups are records of important information that is used often. Backups are kept for a relatively short period of time. Table 3.1 lists the advantages and disadvantages of different types of storage media used for backups.


Backup refers to the process of making copies of data or data files to use in the event the original data or data files are lost or destroyed or storing the copies in a different place from where you keep your computer.

The most popular backup media to use are:

  • External hard drives (HDD): These are quite fast and generally reliable. However, if an external hard drive is used often, the mechanical stress can shorten its lifespan. External hard drives are fragile.
  • External SSDs: SSDs have no moving parts. SSDs are more expensive that hard drives and the storage space is limited due to the cost (the more space you get, the more expensive the SSD becomes).
  • USB flash drives: USB flash drives are cheap and relatively easy to use. There are no moving parts, so they are an excellent way to move data around. However, they can be slow and unreliable.
  • Tapes: Tape backup is copying data from a primary storage device to a tape cartridge so the data can be recovered if there is a hard disk crash or failure. Tape backups can be done manually or be programmed to happen automatically with appropriate software.
  • CDs and DVDs: CDs and DVDs are still occasionally used but writing a CD or DVD is much slower and less convenient than using other media. They have a lower capacity than most flash drives and much lower capacity than portable hard drives.
  • Online storage/backup services: Online data storage is virtually unlimited in size. This means that there is plenty of space for you to back up your entire hard drive, including all of your purchased programs, music, photos, and files. Saving to the cloud means that you are saving to hard drives in a remote location. You must keep your username and password safe in order to protect your data because if someone knows (or even guesses) your credentials, it may result in loss of data.

Archiving, on the other hand, is the long-term storage of information that will be used in future. Archived data is data that is not actively used and is original data that has been removed from its original location. There are several different storage media that can be used for archiving.

Magnetic tape has a very large storage capacity (up to 180 TB), but can be destroyed very easily and the data can be lost.

Online storage is an option and online storage providers (such as Amazon AWS) have relatively inexpensive packages available for storage and archiving.

The data stored in a backup is a copy of the current and active operational data in use by a business. This includes files which are currently being accessed and changed on a regular basis. The files stored on an archive are generally no longer in use, not changing frequently and not required on a regular basis.

image Activity 3.1

1.Multiple choice:

a.Which of the following cannot be used to back up files?

A.External HDD

B.USB drive

C.Optical disc


b.Which of the following is the most expensive storage?





c.Which of the following is secondary storage?





2.Match Column B with Column A:


3.Write True or False next to the question number. Correct the statement if it is FALSE. Change the underlined word(s) to make the statement TRUE. (You may not simply use the word NOT to change the statement.)

a.Primary storage is accessed by the motherboard.

b.Magnetic tape has a very large storage capacity but can be easily destroyed and the data can be lost.

c.Online storage has limited space and you must pay to get more space.

d.The main purpose of primary storage is to store data for a long period of time.

e.Archiving is the short-term storage of information.

4.Answer the following:

a.What is the main purpose of primary storage?

b.Briefly describe the difference between primary and secondary storage.

c.What is the difference between backing up and archiving data?

d.What storage devices would you recommend to someone who needs to store data on a server and someone who wants to store copies of their digital photographs? Motivate your answer.

 3.2   Processing devices

Processing is the second stage of the information processing cycle you learned about in Chapter 1. Processing mainly uses the system components of the computer, such as the motherboard, CPU and RAM, for its tasks. In this unit, you will learn more about the role of each component of a computer system, how they work and what they do.


The motherboard is one of the most essential parts of a computer. It holds many of the components that allow a computer to function, such as the CPU, RAM and the connectors for input and output devices.

Figure 3.1: Computer motherboard with components

The motherboard is made of a thin piece of rigid, non-conductive material. A thin layer of copper or aluminium foil is printed onto the sheet. These circuits are called traces. They are very narrow and form the connections between the various components housed in the motherboard.

The role of the motherboard is to:

  • Provide a place for other devices or interfaces to be installed (such as more memory or another graphics card).
  • Distribute power to the various components.
  • Act as a communication hub as the components send and receive information through the motherboard.


The CPU, which is also called the processor, carries out the instructions of a computer program. It is, basically, the “brain” of the computer and does the arithmetical, logical and input/output operations of a computer program. The speed of the CPU tells you how much data it can process in a specific time. The speed is measured in gigahertz (GHz).

Figure 3.2: Intel Core i7 CPU


All instructions, whether they have been generated by the system or the user, go through the CPU. This could be anything from the operating system executing a task to the user typing letters in a document.


A core is usually the basic computing unit of the CPU. A single core can run a single program, problem or context. A CPU may have one or more cores to perform tasks at any single time. Original CPUs had single cores, but manufacturers began adding more cores to increase the performance of the CPU. A CPU with two cores can split the task into two tasks and thereby complete it faster. This speeds up the computer because it is, essentially, able to multitask.

A dual-core processor has two cores, so it looks like two CPUs to the operating system. A quad-core CPU has four cores, an octa-core CPU has eight cores, and so on. These cores also make sure that the CPU is still small enough to fit into a single socket, taking up less space on the motherboard.


While RAM and ROM are both types of memory, they perform different functions. Table 3.2 compares and contrasts the roles and functions of RAM and ROM.

Table 3.2: Roles and functions of RAM and ROM



When you want to buy a new computer or storage device, there are several key factors to consider. By using what you know about these components, you will be able to interpret the information in advertisements for computers.

Figure 3.3: A computer advertisement

Using what you have learned so far in this chapter, you will be able to interpret any advertisement by looking at the following key pieces of information:

  • How fast is the CPU in the computer? Remember that the faster the CPU works, the faster your computer will be able to process data. So, a 3 GHz processor is twice as fast as a 1,5 GHz one. In this example, the CPU speed is up to 3.10 GHz.
  • How big is the memory? The more RAM you have, the more programs and applications you can run at once. Most computers come with 4 GB of RAM, which is good for users who do not need to do much more than check emails or create some documents. Users who need their computer to do slightly more can look at getting 8 GB of RAM, while 16 GB is good for those who will often be using more memory-intensive programs on their computers (such as games and videos and photo-editing software). In this example, the memory is 8 GB RAM.
  • How much storage capacity does it have? Most computers come with a fairly large hard drive (about 500 GB). You can also buy external hard drives that can store terabytes of data. Make sure you get one that will suit your needs. In this example, the storage capacity is 1 TB.
  • Which operating system does the computer use? The latest operating system will be more compatible with new programs, and will be more secure and able to support the drivers for your hardware. In this example, Windows 10 Home is used.

image Activity 3.2

1.Multiple choice:

a.The start-up process is stored on which hardware component?





b.The speed of a CPU is measured in?




D.Calculations per second

c.The various components of a motherboard are connected by which metal?





2.Match Column B with Column A:


3.Write True or False next to the question number. Correct the statement if it is FALSE. Change the underlined word(s) to make the statement TRUE. (You may not simply use the word NOT to change the statement.)

a.The motherboard distributes power to the computer.

b.The RAM is stored on the BIOS chip.

c.The motherboard is the brain of the computing operation.

d.Temporary files are stored on the CPU.

e.Data stored on the RAM is permanent.

4.Answer the following:

a.Briefly describe the role and function of the motherboard and CPU.

b.Explain RAM.

c.Describe ROM.

d.Which questions should you ask yourself when looking at an advertisement for a computer?

 3.3   Basic troubleshooting

It is important for you to know how to do basic troubleshooting on your storage devices, especially if those devices contain very important information. This unit will look at some basic troubleshooting for storage media.


Most of the basic troubleshooting guidelines for external storage devices can apply to internal storage and processing devices as well, although there are some specific scenarios where advice for storage media will not solve problems with RAM or ROM modules.


Formatting means preparing a disk to store data. Some disks, such as flash disks or hard drives, may need to be reformatted from time to time. Formatting will erase any data that is on the disk, so you will need to back up the data up before you format.

Windows 10 has a built-in disk management tool to make formatting a disk easier.


To format a disk, you must do the following:

Step 1:Click on the Search icon on the bottom left corner of your screen.

Step 2: Type in format.

Step 3: Select Create and format hard drive partitions.

Step 4: This opens the Disk Management dialogue box.

Step 5: Right-click on the disk you want to format and click on Format.

Step 6: Choose NTFS (new technology file system) as the file system and select Default as the Allocation Unit Size.



Disk scans can help detect and fix errors in USB flash drives, hard drives and SSDs. There is a disk scanner built into Windows 10.


To use the disk scanner, do the following:

Step 1: Click on the Search icon on the bottom left corner of your screen.

Step 2: Type in Explorer to open Windows Explorer (or press the Windows key + E).

Step 3: In the File Explorer window, click on This PC in the left navigation pane.

Step 4: A list of drives will be shown in the right window. Right-click on the drive you want to scan and select Properties.

Step 5: In the Properties window, click the Tools tab.

Step 6: Click the Check button in the Error Checking section.

Step 7: Run the scan without any interruptions.

Step 8: You may need to restart your computer if the scan detects any problems.


Over time, the files on your computer’s hard drive become scattered, making your computer slower. This is called disk fragmentation. Defragmenting your hard drive pulls these scattered bits of data back together. Windows 10 automatically defragments your hard drive once a week.

The process of defragmentation moves the data blocks on the hard drive around to bring all the parts of a file together. Defragmentation reduces file system fragmentation, increasing the efficiency of data retrieval and thereby improving the overall performance of the computer. At the same time, it cleans the storage and provides additional storage capacity.


While you are using your computer, you generate many types of files. These files take up space on your computer, making it slower. In Grade 10, you learned how to zip and unzip files, but this may not be enough to speed up your system.

Windows 10 also has a built-in disk cleanup tool that will delete the following:

  • Temporary files from the internet.
  • Deleted files and folders in the recycle bin.
  • Temporary files created by the operating system.
  • The component of the operating system you are not using.
  • Applications or programs that you do not use.
Figure 3.4: Disk cleanup helps with freeing up space on your computer

image Activity 3.3

1.Match Column B with Column A:


2.Write True or False next to the question number. Correct the statement if it is FALSE. Change the underlined word(s) to make the statement TRUE. (You may not simply use the word NOT to change the statement.)

a.Microsoft Windows 10 needs disk scanning software.

b.Formatting your device deletes program files.

c.You must make sure Num Lock is on if your Page Up/Page Down keys are not working.

3.Answer the following questions in your own words:

a.Describe how you would format a disk.

b.What is the purpose of a disk scan?

c.Explain how you would manually defragment your disks.

d.What does the Windows 10 disk cleanup tool do?



1.1Which of the following is an example of primary storage?(1)





1.2Which of the following types of storage is volatile? (1)


B.Internal HDD


D.Internal SSD

1.3Which of the following is involved in the start-up of a computer? (1)





1.4When you look at a computer advertisement, what are the most important things to look at? (1)

A.Storage, operating system, brand

B.Memory, processing speed, external hardware

C.Software, operating system, memory

D.Processing speed, storage, memory

1.5Formatting means ______ a disk to store data. (1)






Write True or False next to the question number. Correct the statement if it is FALSE. Change the underlined word(s) to make the statement TRUE. (You may not simply use the word NOT to change the statement.)

a.Data that is being processed is stored in memory. (1)

b.The more cores a CPU has, the slower it operates. (1)

c.RAM is related to storage, while the CPU is related to speed. (1)

d.Before you format an SD card you must erase the information on it. (1)


Choose a term/concept from Column B that matches a description in Column A. Write only the letter next to the question number (e.g. 1-M). (6)



Fill in the missing word(s) in the following statements. Provide only one word for each space.

a.If you want to delete all the temporary files created by the operating system use i)______ ______. (1)

b.Components on a motherboard are connected with ii)______. (1)

c.The speed of the iii)______ ______ ______ ______, which is measured in GHz, determines how much data your computer can process in a specific time. (1)

d.The CPU fetches instructions from the hardware that need to be iv)______. Then the CPU translates the instructions to v) ______ ______. (2)



Look closely at the advert below and answer the following questions.

5.1What is the speed of the CPU in the computer? (1)

5.2How big is the volatile memory? (1)

5.3How much storage capacity does the computer have? (1)

5.4Which operating system does the computer use? (1)

5.5What does the 15.6” specification in the advert refer to? (1)

5.6What does the 1366 × 768 specification refer to? (1)

5.7What does the SSD acronym stand for? (1)

5.8Give TWO reasons why users would prefer an SSD instead of an HDD? (2)

5.9Suggest ONE way you can use to transfer data from this computer. (1)


Ronaldo has recently bought a new external hard drive for his laptop computer, since his laptop has started running out of space. Ronaldo’s laptop has an SSD with a storage capacity of 500 MB, while his new external hard drive has a storage capacity of 1 GB.

6.1Which of Ronaldo’s storage devices has the longest lifespan? Give one reason for your answer. (2)

6.2When Ronaldo connects his external hard drive to his laptop, his laptop detects it but cannot read it. What should Ronaldo do to work out what is wrong with the external hard drive? (1)

6.3Ronaldo finds out that he should format his new external hard disk. Why should he do this? (1)

6.4Over the past three years, Ronaldo’s laptop has become slower. Mention three things that might be causing this. Also provide a possible solution to each problem. (6)

TOTAL: [40]