Seagate brings terabyte capacity to 2.5'' enterprise storage
 

2.5" hard drives are most commonly associated with notebooks. However, they've also become a staple of server installations looking to cram as much storage as possible into rackmount chassis. Today, Seagate makes that job a little easier with the Constellation.2, which the company says is the first enterprise-class 2.5" model to offer a terabyte of storage capacity.

The Constellation gets to the terabyte mark by stacking four 250GB platters. 2.5" hard drives are typically limited to two platters with the common 9.5-mm drive thickness used for notebooks and three platters for the 12.5-mm spec typical of external hard drives. To accommodate the Constellation's four-storey stack, Seagate uses a drive casing that measures 15 mm in thickness.

http://techreport.com/discussions.x/20116