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Computer Storage devices

Starter questions

  1. Name the two types of computer memory we spoke about last time.

    R_____________ A__________ M_______
    R_____________ O__________ M_______

  2. What else did we call the CPU?


  3. What was the name of the board that all of the parts of a computer connect to?














Learning Intentions

  • To be able to identify different storage types

  • To be able to compare different storage types

Success Criteria

  • I am able to list different storage types and state their benefits

Secondary storage

  • Secondary or backing storage is permanent storage. It’s like our long term memory.

  • We use secondary storage to save things so we can access them at a later date. Without secondary storage, everything we worked on would be lost when we switch off the computer!

Types of secondary storage

  • Today there are many different modes of storing data in your computer. In this lesson we are going to look at:

    1. Hard Disk Drives

    2. Solid State Drives

    3. External Devices

    4. Cloud Storage

Storage over the years

5MB in 1956

1TB in 2014


  • We talk about the amount of storage space in a computer or a device as it’s storage capacity. This is usually measured in bytes (B), kilobytes (KB), megabytes (MB), gigabytes (GB) or terabytes (TB).

    • 1KB = 1000B

    • 1MB = 1000KB

    • 1GB = 1000MB

    • 1TB = 1000GB

  • 1GB is equivalent to about 400 photos, 600 songs or 20 minutes of video.


  • Everything on a computer is stored as binary which means a 1 or 0.

  • For example, the letter a is represented by the binary sequence:

     0100 0001

  • When computers are storing data they store it in binary format.

Types of storage devices

Types of storage devices: hard disk drives

  • A hard disk drive or HDD is still the most common method of storage. This is because of the cost compared to the capacity of these drives.

  • HDDs use a head to read platters of magnetic information. Because of this, they are mechanical drives. A side effect of this is that shaking these drives will likely damage them.

  • Hard drives currently are available of up to 14TB, but the bigger the disk the more likely it is to fail.

Types of storage devices: solid state drives

  • A solid state drive is a drive that has no moving parts, and work very similarly to RAM. Unlike HDDs, shaking these drives does not damage them.

  • Compared with HDDs, these drives are also more power efficient, far faster to read and write to and from.

  • Capacities are also growing quickly, you can now get a 13TB SSD, although at a price of $13,000 (2017). SSDs are more expensive per gigabyte.

  • More and more computers are using SSDs these days. Tablets and smartphones have been using them for years.

Types of storage devices: flash storage

  • Flash drives were once a really big thing. They allowed you to take data with you and plug it into any computer to access it.

  • These have taken a hit because of innovations like the iPad and tablet computers. Can you think why?

  • Memory cards are used in a variety of devices ranging from smartphones, to the Nintendo Switch as well as cameras.

Types of storage devices: discs

  • CompactDiscs (CDs) and Digital Versatile Discs (DVDs) as well as Blu-Ray Discs are also used for storing data.

  • These discs come in several formats including CD/DVD-ROM (read only memory), CD/DVD-R (recordable) and CD/DVD-RW (rewritable).

  • In recent years these have seen a big decline in sales since fewer and fewer computers now have the drives needed to use these discs.

  • CDs and DVDs are fairly easy to scratch and also have low capacities. They also suffer from disc rot.

Complete the rest of the Storage Devices worksheet.


When researching the Internet, remember that there will be a lot of information you do not need. Focus on getting the most important information out of any articles you come across.


Complete the questions on page 274 on storage devices. (green book)


Presentation Overview
Computer storage
© 2020 - 2024 J Balfour
17:10 | 23-05-2024
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