http://www.nytimes.com/aponline/technology/AP-Information-Explosion.h...

March 6, 2007
Tech Researchers Calculate Digital Info
By THE ASSOCIATED PRESS

BOSTON (AP) -- A new study that estimates how much digital information
is zipping around (hint: a lot) finds that for the first time, there's
not enough storage space to hold it all. Good thing we delete some
stuff.

The report, assembled by the technology research firm IDC, sought to
account for all the ones and zeros that make up photos, videos, e-
mails, Web pages, instant messages, phone calls and other digital
content cascading through our world today. The researchers assumed
that an average digital file gets replicated three times.

Add it all up and IDC determined that the world generated 161 billion
gigabytes -- 161 exabytes -- of digital information last year.

That's like 12 stacks of books that each reach from the Earth to the
sun. Or you might think of it as 3 million times the information in
all the books ever written, according to IDC. You'd need more than 2
billion of the most capacious iPods on the market to get 161 exabytes.

The previous best estimate came from researchers at the University of
California, Berkeley, who totaled the globe's information production
at 5 exabytes in 2003. One of the sponsors of that report, data-
storage company EMC Corp., commissioned IDC's new look.

But the Berkeley researchers had taken a different trail. They also
counted non-electronic information, such as analog radio broadcasts or
printed office memos, and tallied how much space that would consume if
digitized. And they examined original data only, not all the times
things got copied.

In comparison, the IDC numbers ballooned with the inclusion of content
as it was created and as it was reproduced -- for example, as a
digital TV file was made and every time it landed on a screen. If IDC
tracked original data only, its result would have been 40 exabytes.

Two researchers who were not involved in the study said that because
IDC used many of its own internal market analyses, the work will be
hard to replicate and confirm. Those researchers, James Short and
Roger Bohn of the University of California, San Diego, plan to use the
Berkeley methods in a follow-up report.

Bohn said it would be wise to take IDC's figures ''with a certain
grain of salt,'' but he added: ''I don't think the numbers are going
to turn out to be wildly off target.''

Considering that Berkeley's 2003 figure of 5 exabytes already was
enormous -- it was said at the time to be 37,000 Libraries of Congress
-- why does it matter how much more enormous the number is now?

For one thing, said IDC analyst John Gantz, it's important to
understand the factors behind the information explosion.

Some of it is everyday stuff in this YouTube age -- IDC estimates that
by 2010, about 70 percent of the world's digital data will be created
by individuals. For corporations, information is inflating from such
disparate causes as surveillance cameras and data-retention
regulations.

Perhaps most noteworthy is that the supply of data technically
outstrips the supply of places to put it.

IDC estimates that the world had 185 exabytes of storage available
last year and will have 601 exabytes in 2010. But the amount of stuff
generated is expected to jump from 161 exabytes last year to 988
exabytes (closing in on 1 zettabyte) in 2010.

''If you had a run on the bank, you'd be in trouble,'' Gantz said.
''If everybody stored every digital bit, there wouldn't be enough
room.''

Fortunately, storage space is not actually scarce and continues to get
cheaper. That's because not everything gets warehoused. Not only do e-
mails get deleted, but some digital signals are not made to linger,
like the contents of phone calls. (Although, who's to say those
conversations don't get catalogued someplace, perhaps the National
Security Agency? The IDC researchers assumed the answer was no. ''I
don't want men in black coming to look for me,'' Gantz joked.)

But even if the IDC findings don't raise the prospect that disk drives
will be virtually bursting at the seams, the study has intriguing
implications. Among them: We'll need better technologies to help
secure, parse, find and recover usable material in this universe of
data.