SanDisk has launched a 32GB solid-state drive using flash memory chips, designed to replace conventional hard disk drives.

Notebooks equipped with the new drive - expected to add around $600 to the cost of a machine - could be available in the first half of 2007, SanDisk said.

Flash memory maker Samsung, announced last May that it would sell laptops with flash-memory drives of a similar capacity. Samsung's drive then added around $1,175 to the cost of its laptop.

The launch of SanDisk's drive means that other notebook computer manufacturers will be able to offer the fast, durable, low-power consumption storage devices made possible by using flash memory.

Until now, large capacity flash-based drives found buyers primarily in the military, aerospace and telecommunications industries, which require systems that can operate under challenging environmental conditions. The declining cost of NAND flash memory, however, has made solid-state drives economically viable in other areas, including notebook computing, SanDisk said

Unlike conventional hard drives, which need to spin into action to seek files, flash memory-based drives contain no moving parts. The 32 GB drive, for instance, can boot up Windows Vista operating system in 35 seconds, compared to 55 seconds for a notebook with a hard disk drive, according to SanDisk. The SanDisk drive also offers average file access rates of 0.12 milliseconds, compared to 19 milliseconds in machines with a hard disk drive.

Another advantage of the flash memory drive, SanDisk said, is its comparatively low power consumption. The chip requires 0.4 watts during active operation compared to 1.0 watts in most hard drives.

SanDisk will offer the drive to equipment manufacturers in a 1.8-inch package.