Storage Showdown

Where data lives

A computer needs somewhere to keep its data, and not all storage is the same. Primary storage sits close to the processor: it includes RAM, which holds the programs and data currently in use but loses everything when the power goes off, and ROM, which keeps the startup instructions permanently. Secondary storage keeps data safely when the power is off, and comes in several kinds with very different strengths. Choosing well means weighing capacity, speed, cost and durability against what you need. This module sets the storage types side by side, compares them, and shows how to choose, including a simple capacity calculation.

Storage words

Learn these terms before the types are compared. They name the kinds of storage and their key property.

Match each storage type to its property

Hard disk against solid-state

The classic storage showdown is the magnetic hard disk against the solid-state drive. Each wins on different measures, which is why both are still used.

Which storage forgets when off?

Which type of storage loses its contents when the power is turned off?

• RAM
• ROM
• A hard disk drive
• A solid-state drive

Choosing the right storage

There is no single best storage, only the best for a need, so a strong answer weighs the factors. Ask how much must be stored, which points to capacity. Ask how fast it must be read, which favours a solid-state drive. Ask what it must cost, which often favours a hard disk. Ask whether it must be carried around or survive knocks, which favours a small, durable device. Then choose the type that best fits. Capacity, speed, cost and durability, weighed against the need: name the factors and justify the choice, and you have answered the question properly rather than just naming a device.

Pick the true storage facts

Select every true statement about computer storage.

• RAM loses its contents when the power is off
• Secondary storage keeps data when the power is off
• A solid-state drive is faster than a hard disk
• ROM loses everything when the power is off
• There is only one type of storage

Order how to choose storage

Put the steps for choosing secondary storage for a need in a sensible order.

• Work out what needs to be stored
• Decide how much capacity is needed
• Decide how fast the access must be
• Weigh the cost, portability and durability
• Choose the type that best fits the need

Complete the storage facts

Storage that loses its contents with no power is _____. Storage that keeps data when the power is off is _____. A drive with no moving parts is a _____ drive. How much data a device can hold is its _____.

One device, one storage choice

Picture choosing storage for a small, rugged action camera that must be light, survive knocks and save video quickly. A spinning hard disk is ruled out at once: it is large and its moving parts would not survive being dropped. An optical disc makes no sense in a camera. A solid-state option fits well, because it is small, has no moving parts to break, and writes video fast, even though it costs more for each gigabyte. Suppose the chosen card holds sixteen gigabytes and each video clip is four gigabytes; dividing the capacity by the clip size shows it can hold four clips. Notice the reasoning: match the storage to what the device actually needs, then check the capacity fits. That is the storage showdown decided on purpose.

Tap the secondary storage

Tap the TWO devices that are types of secondary storage.

• a hard disk drive
• a solid-state drive
• RAM
• the processor

Work out how many files fit

A memory stick holds 16 gigabytes. Each video file is 4 gigabytes. How many of these files fit on it? Divide the capacity by the file size.

Store it wisely

Read each situation and choose the best storage answer.

• A laptop needs storage that is fast, light and durable, and cost is not the main concern. What fits best?
• A user needs the largest possible storage for the lowest cost, and speed matters less. What fits best?
• A program is running right now and its data must be held while in use. Which storage holds it?

Build a point about storage

Choose the word for each gap to complete one clear point about storage.

Explain computer storage

A friend thinks all computer storage is basically the same. Using what you have learned, explain the types of storage and how to choose between them.

• Explain the difference between primary and secondary storage
• Explain what volatile and non-volatile mean
• Explain how a hard disk and a solid-state drive compare
• Explain how to choose storage for a particular need