Page Three

By Peter Coffee  |  Posted 2004-10-25 Print this article Print

Thanks to the intrinsic stability of a mechanical recording medium, IBM has already achieved a Millipede storage density of 125GB per square inch—20 times the current density of magnetic devices and double the predicted theoretical limit of magnetic media.

As a mechanical system, Millipede also offers product designers a direct trade-off between data transfer rate and power consumption. IBM has said that a device based on this technology, with data capacity on the order of 40GB to 80GB and other characteristics competitive with current flash memory units, could be ready to come to market in an SD (Secure Digital)-compatible form factor by 2006 if an overall product road map can be satisfactorily defined.

Enterprise-scale devices have yet to be discussed but seem to eWEEK Labs to be a logical extrapolation of the concept—high density, long lifetime and low power consumption for low-data-rate applications such as offline archival are a compelling set of characteristics.

Familiarity should not breed contempt for the venerable technologies of magnetic tape and solid-state memory. These have long held down opposite ends of the storage spectrum: tape with low cost but with low data throughput to match, solid-state memory with far superior speed but at enormous cost compared with other bulk-storage options.

Storage industry trade associations agree that, by 2006, hard disk storage will cost only 10 times as much per unit of capacity as tape—a significant narrowing of the fortyfold cost advantage that tape had in 1998. This gap will probably not close much further thereafter, however, based on current technology road maps. The hard drive road map, furthermore, will be nearing a probable dead end in terms of further density improvement, while tape manufacturers are not as dangerously close to their magnetic density limits.

eWEEK Labs believes that hard drive technology should initially be used for incremental and weekly backups but that it wont eliminate the need to run full tape backups for off-site storage. Click here to read more. Those with tape experience will know, unfortunately, that mechanical rather than magnetic phenomena are more important to long-term tape performance. Both tape manufacturers and tape-drive builders are exploring the use of microscopic monitoring of the physical condition of tape edges, during both initial production and storage operations, to provide improved manufacturing quality and to minimize data loss by warning of mechanical deterioration during use.

As for solid-state storage devices, its hard to argue with 250 times less latency than a hard disk—except that it comes at a cost of about 1,000 times as much per unit of capacity, making solid-state storage an alluring but generally impractical option.

However, whats working quite well in bandwidth-intensive applications is the use of midsize, solid-state units—typically 16GB to 64GB in size, sometimes configured in arrays—to serve as cache units where many processes access the same data or where theres a high rate of sustained random access.

Sevenfold acceleration of SQL queries, to cite one typical result, can yield good returns on judiciously targeted solid-state storage investments. No single silver bullet, but rather a well-aimed spread, is what it will take for enterprise IT builders to hit their storage targets.

Technology Editor Peter Coffee can be reached at

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Peter Coffee is Director of Platform Research at, where he serves as a liaison with the developer community to define the opportunity and clarify developersÔÇÖ technical requirements on the companyÔÇÖs evolving Apex Platform. Peter previously spent 18 years with eWEEK (formerly PC Week), the national news magazine of enterprise technology practice, where he reviewed software development tools and methods and wrote regular columns on emerging technologies and professional community issues.Before he began writing full-time in 1989, Peter spent eleven years in technical and management positions at Exxon and The Aerospace Corporation, including management of the latter companyÔÇÖs first desktop computing planning team and applied research in applications of artificial intelligence techniques. He holds an engineering degree from MIT and an MBA from Pepperdine University, he has held teaching appointments in computer science, business analytics and information systems management at Pepperdine, UCLA, and Chapman College.

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