..:: 400 GB LAPTOP Hard Disks from Toshiba ::.. Toshiba bested its own 320GB Hard Disk Drive with a 400GB offering in the same 9.5-mm height form factor favored by most thin laptops. The MK4058GSX spins just 2 platters which means the disk sports an impressive 477Mbit/mm2 (308Gbpsi) areal density while consuming 20% less power (0.0015W/GB energy consumption efficiency) and 2dB less noise than its own 320GB predecessor. Rounding out the specs are a 12-ms average seek and 8MB cache. Toshiba also boosted the rest of its 9.5-mm, 2.5-inch, and 3.0Gbps SATA disk lineup to 7,200rpm including the 320GB MK3254GSY....