How Flash Will Change PCs

For the first time in more years than I care to think about, I have been playing around with PCs that have no hard drives. Unlike the clunky floppy-disk-based computers of yore, these are speedy laptops equipped with a new hard-disk alternative called a solid-state drive (SSD), which someday may challenge the hard drive's long run as the storage king.

The SSD is based on the same flash-memory technology found in the widely used USB memory keys. Where a conventional hard drive stores data on a magnetic disk that spins at up to 7,200 rpm, the SSD is basically a handful of chips with no moving parts. Flash has been around for years, but two considerations blocked its use for mass storage: cost and the fact that you could only rewrite your data a limited number of times. Even now, flash memory costs far more per megabyte than magnetic storage, but chip prices have been plunging. As for the limits on rewrites, manufacturers have greatly improved the situation by spiffing up the semiconductors and adding software that makes sure the data in any one chip location aren't changed too often.