|Prefixes for bit and byte|
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). 
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)
There are two different definitions of gigabyte in general use:
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.
|Abbreviation||No. of bytes||Usage|
|gigabytes||GB (Note: uppercase "B")||10003||Computer storage (e. g. , 500 GB hard disk)|
|gigabytes||GB (Note: uppercase "B")||10243||Computer memory (e. g. , 4 GB RAM)|
|gibibytes||GiB (Note: uppercase "B")||10243||Computer storage (e. g. , 34 GiB file)|
|gigabit||Gbit or Gb||125*10002||Network throughput (eg 1 Gbit/s data transfer rate)|
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