Friday, September 23, 2016


The exabyte is a multiple of the unit byte for digital information. The prefix exa indicates the sixth power of 1,000 and means 1018 in the International System of Units (SI), and therefore 1 exabyte is one quintillion bytes (short scale). The unit symbol for the exabyte is EB.

1 EB = 1000000000000000000B = 1018bytes = 1000petabytes = 1 billion gigabytes.

In principle, the 64-bit microprocessors found in many computers can address 16 exabytes of memory.

     1000 kB kilobyte
     10002 MB megabyte
     10003 GB gigabyte
     10004 TB terabyte
     10005 PB petabyte
     10006 EB exabyte
     10007 ZB zettabyte
     10008 YB yottabyte

The world's technological capacity to store information grew from 2.6 (optimally compressed) exabytes in 1986 to 15.8 in 1993, over 54.5 in 2000, and to 295 (optimally compressed) exabytes in 2007. This is equivalent to less than one CD (650MB) per person in 1986 (539 MB per person), roughly 4 CDs per person of 1993, 12 CDs per person in the year 2000, and almost 61 CDs per person in 2007. Piling up the imagined 404 billion CDs from 2007 would create a stack from the earth to the moon and a quarter of this distance beyond (with 1.2 mm thickness per CD).

The world’s technological capacity to receive information through one-way broadcast networks was 432 exabytes of (optimally compressed) information in 1986, 715 (optimally compressed) exabytes in 1993, 1,200 (optimally compressed) exabytes in 2000, and 1,900 in 2007.

The world's effective capacity to exchange information through two-way telecommunication networks was 0.281 exabytes of (optimally compressed) information in 1986, 0.471 in 1993, 2.2 in 2000, and 65 (optimally compressed) exabytes in 2007.

In 2004, the global monthly Internet traffic passed 1 exabyte for the first time. In January 2007, Bret Swanson of the Discovery Institute coined the term exaflood for a supposedly impending flood of exabytes that would cause the Internet's congestive collapse. Nevertheless, the global Internet traffic has continued its exponential growth, undisturbed, and as of March 2010 it is estimated at 21 exabytes per month.

According to the June 2009 Cisco Visual Networking Index IP traffic forecast, global mobile data traffic will grow at a CAGR of 131 percent between 2008 and 2013, reaching over two exabytes per month by 2013. The 2011 update of Cisco's VNI IP traffic forecast, by 2015, annual global IP traffic will reach 966 exabytes or nearly one full zettabyte. Internet video will account for 61% of total Internet data. The February 2013 update of Cisco VNI Forecast for 2012–17, Annual global IP traffic will pass the zettabyte threshold by the end of 2016. In 2016 global IP traffic will reach 1.3 zettabytes per year or 110.3 exabytes per month. By 2017, global mobile data traffic will reach 11.2 exabytes per month (134 exabytes annually); growing 13-fold from 2012 to 2017.

The global data volume at the end of 2009 was 800 exabytes.

161 exabytes of data were created in 2006, "3 million times the amount of information contained in all the books ever written", with the number expected to hit 988 exabytes in 2010.

In the next decade, astronomers expect to be processing 10 petabytes of data every hour from the Square Kilometre Array (SKA) telescope. The array is thus expected to generate approximately one exabyte every four days of operation. According to IBM, the new SKA telescope initiative will generate over an exabyte of data every day. IBM is designing hardware to process this information.

The Digital Britain Report says 494 exabytes of data was transferred across the globe on June 15, 2009.

Several filesystems use disk formats that support theoretical volume sizes of several exabytes, including Btrfs, XFS, ZFS, exFAT, NTFS, HFS Plus, and ReFS.

The ext4 file system format supports volumes up to 1 exabyte in size, although the userspace tools cannot yet administer such filesystems.

A popular expression claims that "all words ever spoken by human beings" could be stored in approximately 5 exabytes of data, (although this project is now outdated and therefore not entirely accurate) often citing a project at the UC Berkeley School of Information in support. 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. This statement has been criticized. Mark Liberman calculated the storage requirements for all human speech at 42 zettabytes (42,000 exabytes, and 8,400 times the original estimate), 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".

Earlier studies from the University of California, Berkeley, 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. 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 that "it would take 9.25 exabytes of storage to hold all U.S. [telephone] calls each year".

International Data Corporation estimates that approximately 160 exabytes of digital information were created, captured, and replicated worldwide in 2006. Research from University of Southern California estimates that the amount of data stored in the world by 2007 was 295 exabytes and the amount of information shared on two-way communications technology, such as cell phones in 2007 as 65 exabytes.

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