Toshiba has expanded its line of 1.8-inch hard drives today with a new dual-platter model that can hold up to 320GB of data -- a world's first in this form factor. The MK3233GSG features a 3Gbps SATA interface and 16MB cache buffer, produces just 19dB of noise during seeks and spins at 5,400 rpm for a maximum transfer rate of 830Mb/s.

The company is positioning its 1.8-inch line as more suitable for portable media devices and thin laptops than competing 2.5-inch drives. According to Toshiba, the tiny storage devices can handle non-operational shock up to 1,500Gs and operational shock up to 500Gs, marking respective improvements of 50 percent and 25 percent. They also consume 42 percent less power when seeking than the best 5,400rpm 2.5-inch HDDs.

There's still no word on pricing but the company says the new MK3233GSG will go into mass production in December 2009. The drives will also be available in 250GB and 160GB versions.