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Gigabyte (GB)

What is a gigabyte?

Anyone who remembers the 1990s knows how astronomically large a hard disk with a Gigabyte (GB) was back then: in 1995, you first had to be able to fill 1000 megabytes of storage space with your data. The term Gigabyte is a compound of the Greek prefix “giga” for billion and “byte” for the smallest addressable unit in computer systems. In this article we explain where the term Gigabyte comes from and how it is used in practice.

What does a Gigabyte (GB) consist of?

Before we look at Byte, we must first take a look at the bit: in computer science, a Byte is a unit composed of eight so-called bits. These bits are, mathematically speaking, the switching states 1 and 0 or physically “current” and “no current”. In the different compositions, the bits generate the different Bytes in which a computer processes the information, stores it in RAM or stores it on a mass storage device (hard disk, SD card).

In the early days of computers, the kilobyte, which is nowadays only relevant for text documents or small images, was the common unit of measurement. Common storage formats at that time, such as the floppy disk, held a few 100 kilobytes up to 1.44 megabytes. With the advent of hard disks, which were initially only a few megabytes in size but quickly reached capacities of hundreds of megabytes, the threshold to the gigabyte, i.e. to a billion Bytes on a data carrier, first became visible on the horizon. By the turn of the 21st century at the latest, hard disks with a storage capacity of one or more Gigabyte (GB) were the common standard in industrial and private computer systems.


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The Gigabyte today: The digital unit of measurement of the 21st century

Today, a memory size of more than one gigabyte, both for fixed mass storage and for working memory, can be found in almost every trouser pocket. Top smartphones today achieve memory sizes of several 100 GB, even the main memories with 4.8 or 16 GB have long since reached the billion-Byte-range.


The actual space required for these formerly astronomically large mass memories is decreasing from year to year: Whereas about 20 years ago a very large and mechanically extremely susceptible hard disk was required for a storage capacity of about 100 Gigabyte (GB), today this quantity fits on a tiny type of memory the size of a human fingernail.

However, the Gigabyte has long since ceased to be the largest storage unit in everyday use. Mass storage sizes of several Terabyte have long since become established in PCs and workstations, and in video editing systems and graphics workstations in particular, memory requirements are growing not just from year to year, but rather from month to month. In the field of Cloud computing, where very large amounts of data are stored on central servers, the unit of measurement petabyte has become established for the enormous amounts of data in server farms. The next largest threshold, the so-called exabyte, was exceeded for global Internet traffic for the first time in 2004. However, it will probably be some time before the domestic PC has an exabyte, i.e. one billion Gigabyte (GB) in its memory. However, this was also said about the megabyte in 1985.

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