A gigabyte (derived from the SI prefix giga-) is a unit of information or computer storage meaning either exactly 1 billion bytes (1000³, or 10⁹) or approximately 1. A bit is a binary digit, taking a value of either 0 or 1 Binary digits are a basic unit of Information storage and communication A byte (pronounced "bite" baɪt is the basic unit of measurement of information storage in Computer science. An SI prefix (also known as a metric prefix) is a name or associated symbol that precedes a unit of measure (or its symbol to form a Decimal multiple or Kilo- (symbol k is a prefix in the SI and other systems of units denoting 103 or 1000 Mega- (symbol M) is an SI prefix in the SI system of units denoting a factor of 106, 1000000 (one Million For other meanings see Giga (disambiguation Giga- (symbol G is a prefix in the SI system of units denoting 109 teras- (symbol T) is a prefix in the SI system of units denoting 1012, or 1000000000000 (1 trillion In Physics and Mathematics, peta- (symbol P) is a prefix in the SI ( System of units) denoting 1015 exa- (symbol E) is a prefix in the SI system of units denoting 1018 or 1 000 000 000 000 000 000 zetta- (symbol Z) is an SI prefix in the SI ( System of units) denoting 1021 or 1 000 000 000 000 000 000 000 yotta- (symbol Y) is an SI prefix in the SI ( System of units) denoting 1024 or 1 000 000 000 000 000 000 000 000 IEC 60027 (formerly IEC 27) is the International Electrotechnical Commission 's standard on Letter symbols to be used in electrical technology. JEDEC Solid State Technology Association, formerly known as J oint E lectron D evice E ngineering C ouncil ( JEDEC) or Joint An SI prefix (also known as a metric prefix) is a name or associated symbol that precedes a unit of measure (or its symbol to form a Decimal multiple or For other meanings see Giga (disambiguation Giga- (symbol G is a prefix in the SI system of units denoting 109 Information as a concept has a diversity of meanings from everyday usage to technical settings Computer data storage, often called storage or memory, refers to Computer components devices and recording media that retain digital A byte (pronounced "bite" baɪt is the basic unit of measurement of information storage in Computer science. 07 billion bytes (1024³, or 2³⁰). ^[1]

The usage of the word "gigabyte" is ambiguous: the value depends on the context. When referring to RAM sizes and file sizes, it traditionally has a binary definition, of 1024³ bytes. In computing binary prefixes are names or associated symbols that can precede a unit of measure (such as a Byte) to indicate multiplication by a power of two For other uses, it means exactly 1000³ bytes. In order to address this confusion, currently the International Electrotechnical Commission (IEC) promotes the use of the term "gibibyte" for the binary definition. The International Electrotechnical Commission ( IEC) is a not-for-profit, non-governmental international Standards organization that prepares and publishes A gibibyte (a contraction of gi ga bi nary byte) is a unit of Information or Computer storage, abbreviated GiB. This position is endorsed by other standards organizations including the Institute of Electrical and Electronics Engineers (IEEE), the International Committee for Weights and Measures (CPIM) and the National Institute of Standards and Technology (NIST). The Institute of Electrical and Electronics Engineers or IEEE (read eye-triple-e) is an international Non-profit, professional organization The International Committee for Weights and Measures is the English name of the Comité international des poids et mesures ( CIPM, sometimes written in English

It is commonly abbreviated GB or Gbyte (not to be confused with Gb, which is used for a gigabit). A gigabit is a unit of information or computer storage abbreviated Gbit (or Gb)

Definition

There are two different definitions of gigabyte in general use:

• 1,000,000,000 bytes or 10⁹ bytes is the decimal definition, used in telecommunications (such as network speeds) and most computer storage manufacturers (such as hard disks and flash drives). Computer data storage, often called storage or memory, refers to Computer components devices and recording media that retain digital A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device This usage is compatible with SI. Quote from Seagate: "For drive storage capacity, 1 gigabyte = 1,000,000,000 bytes (or one billion bytes). ",^[2] Similar quotes are found on the websites of other storage manufacturers.
• 1,073,741,824 bytes, equal to 1024³, or 2³⁰ bytes. This is the definition commonly used for computer memory and file sizes. Microsoft uses this definition to display hard drive sizes,^[3] as do most other operating systems and programs by default. Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination By this definition, there are 1,024³, or 1024×1024×1024 bytes in a gigabyte. (This is equivalent to 1,024 megabytes, where one megabyte is 1,048,576 bytes or 2²⁰ bytes. ) Since 1999, the IEC recommends that this unit should instead be called a gibibyte (abbreviated GiB). The International Electrotechnical Commission ( IEC) is a not-for-profit, non-governmental international Standards organization that prepares and publishes A gibibyte (a contraction of gi ga bi nary byte) is a unit of Information or Computer storage, abbreviated GiB. Although there is little other usage of the term "gigabyte" apart from referring to memory, file sizes, or storage capacity, the IEC's recommendations are frequently ignored amongst computer professionals, and "gigabyte" is used colloquially to mean 1024³ bytes. A colloquialism is an expression not used in formal speech, writing or Paralinguistics. The standard body JEDEC Solid State Technology Association acknowledges the conflict and the existence of the IEC recommendations but, in recognition of the widespread colloquial usage, continues to recognize the definition of 1024³ bytes. JEDEC Solid State Technology Association, formerly known as J oint E lectron D evice E ngineering C ouncil ( JEDEC) or Joint ^[4]

Gigabytes vs. gigabits

In conventional modern usage, a byte is 8 bits. One gigabyte is equivalent to eight gigabits.

In computer networking, however, the conventional SI units are followed. Manufacturers of networking equipment always use 1000-bit kilobits as their basic unit of measurement.

Consumer confusion

As of 2007, most consumer hard drives are defined by their gigabyte-range capacities. In telecommunications Bit rate or Data transfer rate is the average number of Bits characters or blocks per unit time passing between equipment in a data transmission A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device The true capacity is usually some number above or below the class designation. Although most manufacturers of hard disks and Flash disks define 1 gigabyte as 1,000,000,000 bytes, the computer operating systems used by most users usually calculate a gigabyte by dividing the bytes (whether it is disk capacity, file size, or system RAM) by 1,073,741,824. This distinction is a cause of confusion, as a hard disk with a manufacturer rated capacity of 400 gigabytes may have its capacity reported by the operating system as only 372 GB, depending on the type of report.

The difference between units based on SI and binary prefixes increases exponentially — in other words, an SI kilobyte is nearly 98% as much as a kibibyte, but a megabyte is under 96% as much as a mebibyte, and a gigabyte is just over 93% as much as a gibibyte. This means that a 500 GB hard disk drive would appear as "465 GB". As storage sizes get larger and higher units are used, this difference will become more pronounced.

Note that computer memory is addressed in base 2, due to its design, so memory size is always a power of two (or some closely related quantity, for instance 384 MiB = 3×2²⁷ bytes). The binary numeral system, or base-2 number system, is a Numeral system that represents numeric values using two symbols usually 0 and 1. In Mathematics, a power of two is any of the Integer powers of the number two; in other words two multiplied by itself a certain It is thus convenient to work in binary units for RAM at the hardware level (for example, in using DIMM memory units). A DIMM, or dual in-line memory module, comprises a series of Dynamic random access memory Integrated circuits These modules are mounted on a Printed RAM memory size as seen by application software has no consistent bias towards power of two units, as the operating system will allocate memory in other granularities. Other computer measurements, like storage hardware size, data transfer rates, clock speeds, operations per second, etc. Computer data storage, often called storage or memory, refers to Computer components devices and recording media that retain digital Data transmission is the transfer of Data from point-to-point often represented as an Electro-magnetic Signal over a physical point-to-point or point-to-multipoint The clock rate is the fundamental rate in cycles per second (measured in Hertz) at which a Computer performs its most basic operations such as adding two Measuring performance In order for FLOPS to be useful as a measure of floating-point performance a standard benchmark must be available on all computers of interest , do not have an inherent base, and are usually presented in decimal units. radix|basis (topologyIn Arithmetic, the base refers to the number b in an expression of the form b n.

An example, take a hard drive that can store exactly 250×10⁹ or 250 billion bytes after formatting. Generally, operating systems calculate disk and file sizes using binary numbers, so this 250 GB drive would be reported as "232. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination 83 GB". The result is that there is a significant discrepancy between what the consumer believes they have purchased and what their operating system says they have.

Some consumers feel short-changed when they discover the difference, and claim that manufacturers of drives and data transfer devices are using the decimal measurements in an intentionally misleading way to inflate their numbers. Several legal disputes have been waged over the confusion. See Binary prefix — Legal disputes. In computing binary prefixes are names or associated symbols that can precede a unit of measure (such as a Byte) to indicate multiplication by a power of two

To further complicate matters, flash memory chips are organized in multiples of 2, but retail flash memory products have available capacities specified by multiples of 10. Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed Removable flash storage products contain file systems that make the devices behave like hard disks instead of RAM, yet it is called 'memory'. In operating systems like Windows Vista, flash memory can indeed be treated like RAM. Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops

The basis of the problem is that the official definition of the SI units is not well known, and some legal settlements include directions for manufacturers to use clearer info, e. g. by stating a hard disk's size in both GB and GiB. However, JEDEC memory standards still uses the IEEE 100 nomenclatures. The JEDEC Solid State Technology Association is the semiconductor engineering standardization body of the Electronic Industries Alliance (EIA

Gigabytes in use

• The human genome contains 0. The human genome is the Genome of Homo sapiens, which is stored on 23 chromosome pairs 791175 GB of data (the 3. 1647×10⁹ base pairs[1] represented as 2-bits). In Molecular biology, two Nucleotides on opposite complementary DNA or RNA strands that are connected via Hydrogen bonds are called A bit is a binary digit, taking a value of either 0 or 1 Binary digits are a basic unit of Information storage and communication
• A DVD-5 format disc is specified as capable of storing 4. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is 7 gigabytes (4,700,000,000 bytes), or roughly 4. 38 gibibytes. A gibibyte (a contraction of gi ga bi nary byte) is a unit of Information or Computer storage, abbreviated GiB. A DVD-9 is capable of storing 8. 5 gigabytes, or roughly 7. 91 gibibytes.
• One gigabyte can hold over 1000 novels (uncompressed at 100,000 words per novel).
• One gigabyte is roughly equal to 17 hours of MP3 music at 128 kbit/s (1,000³ / 128 / 1000 * 8 / 3600 = 17. MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a Digital audio encoding format using a form of Lossy data compression 36).
• One gigabyte is roughly equivalent to 12 hours of Flash Video (at 450x370). Flash Video is the name of a File format used to deliver Video over the Internet using Adobe Flash Player (initially produced
• All 6th generation and 7th generation game consoles have game discs that are around 1 GB or more: Dreamcast (GD-ROM - 1. The sixth-generation era (sometimes referred to as the 128-bit era; see "Number of bits" below refers to the computer and Video games In the History of video games, the seventh generation, which is also the current generation primarily focuses on the consoles released since by Nintendo, The is Sega 's most recent Video game console and the successor to the Sega Saturn. GD-ROM (an abbreviation of " giga disk Read-only memory " is the proprietary Optical disc format used by the Sega Dreamcast. 2 GB), Nintendo GameCube (MiniDVD - 1. The, often abbreviated as GCN, is Nintendo 's fourth home Video game console and is part of the sixth generation console era. There are two types of MiniDVDs. 80 mm DVD, which are smaller versions of the 120 mm DVD cDVD, which are standard 5 GB), PlayStation 2, Xbox, Xbox 360, and Wii (DVD - 8. The Xbox is a sixth-generation Video game console produced by Microsoft Corporation. The Xbox 360 is the second Video game console produced by Microsoft, and was developed in cooperation with IBM, ATI, and SiS. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is 5 GB), and PlayStation 3 (Blu-ray Disc - 50 GB).
• Dual-layer Blu-ray Discs can hold about 50 gigabytes (50,000,000,000 bytes), dual-layer HD DVD discs 30 gigabytes (30,000,000,000 bytes) of data. not insert the publicly disclosed HD DVD key into this article for the time being

See also

• Binary prefix
• JEDEC memory standards
• Orders of magnitude (data)

References

1. ^ 1000³ = one billion. In computing binary prefixes are names or associated symbols that can precede a unit of measure (such as a Byte) to indicate multiplication by a power of two The JEDEC Solid State Technology Association is the semiconductor engineering standardization body of the Electronic Industries Alliance (EIA This is a list of orders of magnitude for Data (or Information) measured in Bits This article assumes a descriptive attitude towards terminology reflecting
2. ^ Industry Terms Glossary: Gigabyte.
3. ^ HP Notebook PCs - Size of Disk Drive Does not Match Specifications (Windows XP).
4. ^ JEDEC Solid State Technology Association (December 2002), “Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits”, JESD 100B. 01, <http://www.jedec.org/download/search/JESD100B01.pdf> 

External links

• http://physics.nist.gov/cuu/Units/binary.html
• http://www.iec.ch/zone/si/si_bytes.htm
• http://www.quinion.com/words/turnsofphrase/tp-kib1.htm
• http://www.nist.gov/public_affairs/techbeat/tb9903.htm