Binary and data representation - EdexcelData storage and compression

All data in a computer is represented in binary, whether it is numbers, text, images or sound. The computer software processes the data according to its content.

Part ofComputer SciencePrinciples of computer science

Data storage and compression

Calculating storage space is helpful when managing projects as it helps the user to know how much they can store.

Example

There are 150 music files, each of which is approximately 6 megabytes (6 MB) in size. There's a 1 gigabyte (1 GB) USB memory stick on which these files are to be stored. In order to work out how much storage space is required to store all these files on the stick, the following calculation can be used:

150 x 6 megabytes = 900 megabytes

To determine whether the USB memory stick has enough capacity to store all 150 music files, the units used for both the files and the storage device need to be the same.

The size of the music files is in megabytes, so the capacity of the USB will also need to be converted to megabytes.

In this example, the USB memory stick has a 1 gigabyte (GB) capacity:

1 gigabyte (GB) = 1,000 megabytes (MB)

The capacity of the USB memory stick is now expressed in megabytes. The following calculation will determine how many 6 megabyte (mb) files this storage device can hold:

1000 / 6 = 166.66 files

As there are 150 music files, they will all fit on the USB memory stick.

This process can be applied to files of any type and size, as shown in the table below show:

File typeAverage size (approx.)Quantity held in 1 gigabyteCalculation
Word processed document100 kilobytes (KB)1 gigabyte (GB) = 1,000 megabytes (MB). 1000 megabytes (MB)= 1,000,000 kilobytes (KB).1,000,000 / 100 = 10,000 word processed files
Image file2 (MB)1 gigabyte (GB) = 1,000 megabytes (MB).1,000 / 2 = 500 image files
Video file100 megabytes (MB)1 gigabyte (GB) = 1,000 megabytes (MB)1,000 / 100 = 10 video files
File typeWord processed document
Average size (approx.)100 kilobytes (KB)
Quantity held in 1 gigabyte1 gigabyte (GB) = 1,000 megabytes (MB). 1000 megabytes (MB)= 1,000,000 kilobytes (KB).
Calculation1,000,000 / 100 = 10,000 word processed files
File typeImage file
Average size (approx.)2 (MB)
Quantity held in 1 gigabyte1 gigabyte (GB) = 1,000 megabytes (MB).
Calculation1,000 / 2 = 500 image files
File typeVideo file
Average size (approx.)100 megabytes (MB)
Quantity held in 1 gigabyte1 gigabyte (GB) = 1,000 megabytes (MB)
Calculation1,000 / 100 = 10 video files