Samsung has developed what it says could be a replacement for conventional hard-disk drives on Flash memory chips. Mass production will start in August.

The solid-state disk (SSD) uses memory chips instead of the mechanical recording system used inside most hard-disk drives, and has several advantages including lower power consumption and higher data rates.

Flash memory technology isn't new and the advantages have been known for years but such solid-state disks have never been commercially produced before because Flash is so much more expensive.

Samsung announced basic details of the SSD but, crucially, refused to give information about its price.

The company is planning SSDs with parallel ATA interfaces in capacities up to 16GB. The 16GB devices will contain 16 memory chips, it said. Such chips sell for about $55 each on the spot memory market, according to DRAM Exchange - putting the cost of the 16GB drive at a hefty $900.

Because Samsung is a major manufacturer of flash memory chips, it can likely source the chips internally at a lower price. Even so, it will be difficult to compete with hard-disk drive makers on cost. Laptop drives at capacities of up to 30GB can easily be found for less than $200.

The SSD operates silently, consumes five percent of the power used by a hard disk, and weighs less than half as much. It can read data at up to 57Mbit/s and write it at up to 32Mbit/s.

Because SSDs don't use moving parts, they are much more resistant to harsh environmental conditions or shock and are thus suitable for industrial or military markets, said Samsung. Such users are less focused on low-cost components than the consumer market.

Samsung expects the SSDs will find a home in specialised portable products such as tablet PCs or laptops, said a spokeswoman. Three versions are planned: a 16GB version that will be about the same size as a 2.5in hard-disk drive, and 8GB and 4GB versions that will be a similar size to 1.8in drives.

The price difference between flash memory and hard-disk storage has been narrowing and continues to do so, said Simon Woo, an analyst at Merrill Lynch in Seoul. While per-bit prices for the type of memory produced by Samsung are dropping at between 30 percent and 40 percent per year, the equivalent price for hard-disk storage is falling by about 20 percent annually, he said.

Eventually, SSDs will be able to compete with hard-disk storage on price but that time is several years away, he added.