In today's computer-savvy age, computer chips have brand names, Internet users debate the merits of cable modems vs. DSL phone lines and the introduction of a new operating system, such as the release of Windows XP, is a national news story.
But nobody thinks much about the hard-disk drive. As critical to the popularity of PCs as fast, cheap microprocessors and the Internet, these data storage devices whirl away anonymously inside computer cabinets, filing away e-mails, computer games and downloaded photographs. And for the past decade, the amount of data that can be magnetically stored within a square inch of disk has more than doubled annually, a fact that is as amazing as it is taken for granted.
So it's news to most of us that the jig is up.
Hard disks aren't going away any time soon, but those days of spectacular growth in storage capacity will soon be over. Engineers, bumping up against the physical limits of conventional hard disks, are looking for new storage technologies.
"We don't know exactly when recording will run out of steam," said Mark Kryder, research director for Seagate Technologies, a major hard-disk maker. "We have thousands of clever engineers who will extend it as far as we can." But within two or three years, advances in storage capacity will begin to taper off, he predicted.
"In the labs, we've all seen the effect," Kryder added.
In late October, Carnegie Mellon University announced that the U.S. Department of Commerce had agreed to help fund a five-year, $21.6 million effort led by Seagate and Carnegie Mellon's Data Storage Systems Center to develop an enhanced data storage technology, called heat-assisted magnetic recording.
If researchers can pull it off, the new technology could store at least 100 times more data in a square inch than has been achieved with today's hard disks.
"It's a huge challenge," said Ed Schlesinger, a professor of electrical and computer engineering who, with James Bain, will lead the Carnegie Mellon portion of the program. Researchers will have to sort out the strange physical properties that apply to materials and light at scales smaller than a virus.
A leveling-off of the exponential growth of hard-disk recording capability wouldn't seem to be a crisis. After all, hard-disk drives could continue to do everything that they do today.
But continued improvements in data storage, much like development of faster microprocessors, drive down the costs of computing and make new applications possible.
Take television, for instance. Cheap hard-disk storage makes personal video recorders such as Tivo possible. These devices make it possible to record multiple TV programs simultaneously, or to seemingly "pause" live TV.
"My expectation is that 10 years from now you will not buy a TV set without a personal video recorder built in," Kryder said. Placing hard disks in TVs could alone double the size of the $35-billion-a-year industry.
High-definition televisions now on the horizon will make such devices essential, said Robert White, director of the Data Storage Systems Center. Today's videocassette recorders simply won't work with HDTV, he noted, and even DVDs may not be good enough to match HDTV's demands.
As the density of data on a hard disk grows, the size of the disks themselves can shrink. IBM already is selling a Microdisk that can store a gigabyte of information - 1 billion computer words, or "bytes" - on a device measuring not much more than an inch square. Hard-disk drives could be built into cars, hand-held audio devices and any number of machines and appliances.
Some people envision a "memory prosthesis," a handheld device that could record everything a person sees, hears or does in the course of a day.
Work is under way at Carnegie Mellon to develop wireless hard-disk drives, White said, a development that, combined with ever-cheaper disk drives, could usher in an era of "ubiquitous computing." Rather than relying solely on a computer's own hard disk, future computer users would tap into a shared storage utility, consisting of interlinked, wireless hard drives that could provide data storage on demand.