Now its Zetabytes ... PetaBytes storage capacity is nowhere

Every man, woman and child on the planet using micro-blogging site Twitter for a century. For many people that may sound like a vision of hell, but for watchers of the tremendous growth of digital communications it is a neat way of presenting the sheer scale of the so-called digital universe. The explosion of social networking, online video services and digital photography, plus the continued popularity of mobile phones, email and web browsing, coupled with the growing desire of corporations and governments to know and store ever more data about everyone has created an unprecedented amount of digital information and introduced a new word to the nerd lexicon: a zettabyte.


Research published today estimates that the so-called digital universe grew by 62% last year to 800,000 petabytes - a petabyte is a million gigabytes – or 0.8 zettabytes. That is the equivalent of all the information that could be stored on 75bn Apple iPads, which would equal the digital output from a century's worth of constant tweeting by all of Earth's inhabitants.

By way of stark contrast between the output of present day humanity and its pre-digital predecessor, experts estimate that all human language used since the dawn of time would take up about 5,000 petabytes if stored in digital form, which is less than 1% of the digital content created since someone first switched on a computer.This year, the planet's digital content will blast through the zettabyte barrier to reach 1.2 ZB, according to the fourth annual survey of the world's bits and bytes conducted by technology consultancy IDC and sponsored by IT firm EMC. A zettabyte, incidentally, is roughly half a million times the entire collections of all the academic libraries in the United States.

As an increasing number of "old media" stalwarts, such as book publishing, migrate to new online platforms the digital universe is set to expand further. The upgrading of existing digital content - such as the production of high definition television, Blu-Ray DVD and 3D films - will also expand the world's store of electronic information. Consumers, meanwhile, are expected to continue their love affair with social networking, video sharing and their host of devices that can create, store and share content, such as digital cameras and mobile phones.

"There has been mammoth growth in the types of media that make up the digital universe," according to Adrian McDonald, vice president and general manager for UK & Ireland EMC. "A huge increase in video and digital photography – in the old days people would take one photograph, now they can knock off 20 photos and rather than store just one, people store all 20 and then they store all 20 many times across the web. Then there is the fact that the number of devices where information can be generated and stored has also increased."

As a result, over the next decade, the information contained within the digital universe is forecast to expand by a factor of 44, according to the survey.

Mobile phones have dramatically widened the range of people who can create, store and share digital information.

"China now has more visible devices out on the streets being used by individuals than the US does," said McDonald. "We are seeing the democratisation and commoditisation of the use and creation of information."

But the expanding digital universe will present companies with a headache as the generation of content far outstrips the capacity of corporate storage and the world's IT professionals run to keep up with demand for their services. About 70% of the digital universe is generated by individuals, but its storage is then predominantly the job of corporations. From emails and blogs to mobile phone calls, it is corporations that are storing information on behalf of consumers.

Then there are the actions in the offline world that individuals carry out which result in digital content being created by organisations – from cashpoint transactions which a bank must record to walking along the pavement, which is likely to result in CCTV footage.

The vast majority of this information, meanwhile, is "unstructured", which means it has not been specifically created so it can easily be indexed, sorted, catalogued and retrieved.

Corporations are spending increasing amounts of money on technology from companies such as Cambridge-based Autonomy, which allows them to search through such mounds of information. Individuals, however, are likely to rely ever more heavily on the large internet search engines, especially Google, as much of their own personal content will increasingly be stored and searched online.

EMC and IDC first examined the digital universe back in 2007 and estimated that it was equivalent to 161 exabytes, 161,000 petabytes or 161bn gigabytes. At the time they forecast the digital universe would grow to 988 exabytes, just under 1 zettabyte, by this year. The fact that growth has been faster than expected even in that short period of time comes as little surprise to a veteran of the rapidly changing IT industry such as McDonald.

"I'm not that old, but we used to sell memory boards in 16 kilobytes – not even megabytes. And that was a big board which you sold into a serious company. I used to sell systems that were 50 megabytes. Even USB flash memory sticks are larger than that now," he said.

"You talk to a kid these days and they have no idea what a kilobyte is. The speed things progress, we are going to need many words beyond zettabyte."