Perpendicular Equals Greater Storage

Fortunately for mobile users, Seagate Technology has incorporated perpendicular recording technology into its new line of 2.5-inch Momentus hard drives.

Available in capacities as high as 160 Gbytes, the perpendicular recording technology leaves plenty of room for improvement and greater capacity down the road. The Momentus 5400.3 160-Gbyte model costs $325.

According to Seagate engineers, disk manufacturers hit a wall about three years ago trying to increase the capacity of 2.5-inch hard drives. Magnetically charged bits spaced too closely can affect one another such that a change in the state of one bit might unintentionally force a change to an adjacent bit. Desktop drives with 3.5-inch platters don’t pack the bits in quite as tightly and don’t exhibit crosstalk.

Seagate started working on perpendicular recording technology.

Perpendicular recording leaves data bits standing on end rather than flat, as is the case with longitudinal recording. Perpendicular recording improves performance without increasing spin speed and power consumption because more of the tightly packed bits can pass under the drive head in the same amount of time.

Areal density is also key.

Longitudinal recording allowed a maximum areal density of 91.5 bits per square inch, which allowed for 2.5-inch drives as capacious as 120 Gbytes. Perpendicular recording increases areal density to 132 bits per square inch and a maximum capacity of 160 Gbytes.

All of Seagate’s Momentus 5400.3 hard drives feature a 100-MBps Ultra ATA interface; models with 1.5-Gbps Serial ATA interfaces will become available later this year.

Seagate’s drives can withstand up to 350 Gs of operating shock and 900 Gs of non-operating shock. The drives are covered by a five-year warranty for system builders that buy through authorized distribution.