Guardian Unlimited Business — How one year’s digital output would fill 161bn iPods

Richard Wray — 6 March 2007
Last year enough digital information - from emails and blogs to mobile phone calls, photos and TV signals - was generated to fill a dozen stacks of hardback books stretching from the earth to the sun, according to research published today.

The proliferation of digital cameras and mobile phones that can take pictures, coupled with the popularity of online video services such as YouTube and BitTorrent, has caused an explosion of images. This pushed the world’s total digital content last year to 161bn gigabytes. That is the equivalent of 161bn iPod Shuffles or 161 of so-called exabytes

Why “so-called” exabytes? Isn’t this an accepted term? Is it something else — an overbite, perhaps — masquerading as an exabyte?

I like the “161bn”, too. Given the myriad assumptions and blind guesses needed in an exercise like this, “roughly 160 billion” is probably the best one could get (and “something over 150 billion” possibly more realistic). It’s what my old physics master used to call the fallacy of spurious accuracy.

Editorial weirdness apart, the article looks to have done a decent job of summarising the results of this study. Unfortunately it does not give its title, so the original can’t easily be tracked down for more detail. Also, neither the EMC or IDC Web site mentions it.

This report’s results are destined to become factoids [1], quoted in countless (even by IDC) publications, presentations and Web sites. It’s a pity therefore that we don’t have on the day of its release the details of how these numbers were arrived at.

The last large-scale study of this kind was made three years ago by researchers at the University of California, Berkely. Called How Much Information? 2003, it estimated the amount of data produced by machines in 2002 at around 5 exabytes. (No “so-called” needed then, note.) This included 0.42 exabytes of original content held on film used in still, X-ray and movie cameras.

Ignoring film therefore, the estimated total of new digital data in 2002 was just over 4.5 exabytes. In 2005, according to IDC, email traffic alone amounted to 6 exabytes.

Even though the academic and the IDC researchers probably went about their work in different ways, a rough comparison of these two sets of results gives an idea of just how much data we’re producing and throwing around the place. It’s astonishing.

[1] There are a couple of rants about factoids here and here.

18 March 2007
I’ve just a had a look at the EMC site and it now has details of the survey on it — prominently displayed, in fact. Y0u can download the IDC white paper from here and read more about the topic here.