Samsung has begun shipping a flash memory-based solid state disk drive (SSD) that offers better performance than many of the flash drives currently available, the company said.

The 64GB 1.8-inch drive has a SATA II interface that can support data reading at speeds of 100Mbps (bytes per second) and writing at 80Mbps. That makes it 60 per cent faster than SATA I drives of the same type and two to five times faster than conventional hard-disk drives, according to Samsung.

SSDs use flash memory rather than magnetic storage, which means faster reading and writing of data, lower power consumption and zero noise. They've been around for several years although it is only recently, after flash memory chip prices fell, that they have become practical for use in laptop computers.

The drives were announced back in November when Samsung started supply samples of the drives to computer makers. Commercial versions of the drive are now available and will be offered as options on some Dell and Alienware laptops in the coming weeks, said Samsung. Prices were not announced.

Samsung is also planning to target the enterprise server market and other applications that demand high-speed data transfer.

Despite their advantages over hard-disk drives, SSDs are only taking off slowly because they are much more expensive. To get around this problem Samsung showed a 128GB SSD based on MLC (multi-level cell) NAND flash, at the recent International Consumer Electronics Show in Las Vegas. It's a cheaper but not as powerful or efficient version of flash chip than the SLC (single level cell) used in most SSDs drives until now. The SLC-type memory chips last about ten times as long as MLC chips.

The SATA II connection works with standard SATA I or II ports but not with the MacBook Air, which employs a Parallel ATA connector.