Data Capacity & Calculating Capacity Requirements (OCR GCSE Computer Science)
Revision Note
Written by: Robert Hampton
Reviewed by: James Woodhouse
Data Capacity & Calculating Capacity Requirements
What is data capacity?
Data capacity is the maximum amount of information that a storage device can hold
If you know the capacity of a storage device, you can calculate how much of different data types can be stored
Examples of data that could be stored include text, images and sound files
How do you calculate capacity requirements?
To calculate capacity requirements you need to:
Know the capacity of the storage device
Calculate the size of a file (formula)
Ensure the same units of data storage are used for capacity and size of the file, else convert between units to get them to be the same
Divide the capacity by size of the file being stored
The image above shows common capacities of storage devices such as hard drives (HDD), USB flash drives, solid state drives (SSD) and optical disks (CD)
Calculating file sizes
Text Files | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
(Bytes per character) x (Number of characters) | ||||||||||||
|
Image Files | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
(Resolution) x (Colour Depth) | ||||||||||||
|
Sound Files | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
(Sample Rate) x (Duration in seconds) x (Bit Depth) | |||||||||||||||
|
Worked Example
Lyla is a social media influencer. She creates images to be shared on her social media accounts.
Each image has a fixed size of 3 MB. She is storing the images on a USB flash drive which has a capacity of 6 GB.
Calculate how many images can be saved on the storage device. Show your working [2]
How to answer this question:
Convert 6 GB to MB
Divide the capacity in MB by the files size in MB
Answer
6 GB = 6 * 1000 = 6000 MB
6000 / 3 = 2000 images
Last updated:
You've read 0 of your 5 free revision notes this week
Sign up now. It’s free!
Did this page help you?
