According to Toshiba, the 1.8" form factor is more robust than the 2.5" one regarding vibration and shock resistance, but it suffers a lower global performance.

To provide an improvement in this section of the market, Toshiba announced a new series of 1.8" HDDs. Featuring a SATA interface and a higher rotational speed, these new drives are claimed to greatly improve performance. Moreover, a higher capacity has been obtained further, making this form factor even more interesting for portable devices.

The new line included two drives, a 160GB drive, MK1617GSG, and a 80GB drive, MK8017GSG. Both products will enter mass production in August.

The new MK1617GSG drive is also claimed to be more environmentally efficient than Toshiba's current MK1216GSG (120GB) model, and raises energy consumption efficiency, as defined under the Japanese legal standard, to 0.00281W/GB, a 25% improvement. The drive improves the maximum internal data transfer rate by approximately 17%, and supports faster data access in reading and writing that enhances overall performance.

More detailed specifications can be found here.