Exabyte
From Wikipedia, the free encyclopedia
- For the company that manufactures data backup products, see Exabyte Corporation.
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|---|---|---|---|---|
| SI prefixes | Binary prefixes | |||
| Name (Symbol) |
Standard SI |
Alternate Use |
Name (Symbol) |
Value |
| kilobyte (kB) | 103 = 10001 | 210 | kibibyte (KiB) | 210 |
| megabyte (MB) | 106 = 10002 | 220 | mebibyte (MiB) | 220 |
| gigabyte (GB) | 109 = 10003 | 230 | gibibyte (GiB) | 230 |
| terabyte (TB) | 1012 = 10004 | 240 | tebibyte (TiB) | 240 |
| petabyte (PB) | 1015 = 10005 | 250 | pebibyte (PiB) | 250 |
| exabyte (EB) | 1018 = 10006 | 260 | exbibyte (EiB) | 260 |
| zettabyte (ZB) | 1021 = 10007 | 270 | zebibyte (ZiB) | 270 |
| yottabyte (YB) | 1024 = 10008 | 280 | yobibyte (YiB) | 280 |
An exabyte (derived from the SI prefix exa-) is a unit of information or computer storage equal to one quintillion bytes. It is commonly abbreviated EB. When used with byte multiples, the SI prefix may indicate a power of either 1000 or 1024, so the exact number may be either:
- 1,000,000,000,000,000,000 bytes — 10006, or 1018, or
- 1,152,921,504,606,846,976 bytes — 10246, or 260.
The term "exbibyte", using a binary prefix, has been proposed as an unambiguous reference to the latter value.
As of 2007, exabytes of data are almost never encountered in any practical context, except to refer to the address space of 64-bit architectures as 16 exabytes.[1]
Contents |
[edit] Popular expression
A popular expression claims that "all words ever spoken by human beings" could be represented by approximately 5 exabytes of data,[2][3][4] often citing a project at the UC Berkeley School of Information in support.[5] The 2003 University of California Berkeley report credits the estimate to the website of Caltech researcher Roy Williams, where the statement can be found as early as May, 1999.[6] This statement has been criticized.[7][8] Mark Liberman calculated the storage requirements for all human speech at 42 zettabytes, if digitized as 16 Khz 16-bit audio, although he did "freely confess that maybe the authors [of the exabyte estimate] were thinking about text".[9]
Earlier Berkeley studies estimated that by the end of 1999, the sum of human-produced information (including all audio, video recordings and text/books) was about 12 exabytes of data.[10] The 2003 Berkeley report stated that in 2002 alone, "telephone calls worldwide on both landlines and mobile phones contained 17.3 exabytes of new information if stored in digital form", and "it would take 9.25 exabytes of storage to hold all U.S. [telephone] calls each year."[5] International Data Corporation estimates that 161 exabytes of digital information were created, captured, and replicated worldwide in 2006.[11]
The word exabyte is the basis for the term "exaflood", a neologism created by Bret Swanson of the Discovery Institute in a January 2007 Wall Street Journal editorial.[12] It describes a possible future scenario where growth and demand for high-definition video exceeds current bandwidth capacity, particularly if network neutrality laws have a detrimental effect on investment in new broadband networks.
[edit] In fiction
In the Star Trek: The Next Generation episode The Measure of a Man, the fictional character Data, an android, is said to have a storage capacity of 800 quadrillion bits (100 x 1015 bytes), or about 0.1 exabytes (100,000 terabytes). Later episodes of the Trek franchise began to use fictional quads (and SI prefix derivatives) as the basic units of computer storage capacity.
[edit] See also
[edit] References
- ^ A brief history of virtual storage and 64-bit addressability. Retrieved on February 17, 2007.
- ^ Klinkenborg, Verlyn (November 12, 2003). Trying to Measure the Amount of Information That Humans Create. New York Times. Retrieved on July 19, 2006. (login)
- ^ How many bytes for.... techtarget.com. Retrieved on July 19, 2006.
- ^ 'Robbie the Robot' making data easier to mine. purdue.edu (December 6, 2005). Retrieved on February 17, 2007.
- ^ a b How Much Information? 2003. berkeley.edu. Retrieved on July 19, 2006.
- ^ Williams, Roy. Data Powers of Ten. Archived from the original on 1999-05-08. Retrieved on July 19, 2006.
- ^ More on the 5 exabyte mistake. upenn.edu (November 12, 2003). Retrieved on July 19, 2006.
- ^ Carnell, Brian (December 31, 2003). How Much Storage Is Required to Store Every Word Ever Spoken by Human Beings?. brian.carnell.com. Retrieved on July 19, 2006.
- ^ Liberman, Mark (November 3, 2003). Zettascale Linguistics. upenn.edu. Retrieved on February 17, 2007.
- ^ Enriquez, Juan (Fall/Winter 2003). The Data That Defines Us. CIO Magazine. Retrieved on July 19, 2006.
- ^ Bergstein, Brian (March 5, 2007). So much data, relatively little space. BusinessWeek. Retrieved on March 5, 2007.
- ^ Swanson, Bret (January 20, 2007). The Coming Exaflood. Wall Street Journal. Retrieved on February 17, 2007.
