Ever since the introduction of desktop hard drives with capacities of 200 and 250 GB, the pace of capacity boosts has quickened. With a total storage capacity of half a teraByte, Hitachi breaks through into impressive terrritory without increasing data density on its drive platters.
It's typical that data density increases with each new generation of hard disks. This value is normally expressed either in terms of gigabytes per platter, or gigabytes per unit of surface measurement (usually square inches or centimeters). At present, typical values usually fall somewhere between 100 GB and 133 GB per platter. At any time, adding more platters to a drive is the easiest way to increase total capacity.
Even though Seagate now offers the highest data densities available at 133 GB per drive platter, Hitachi won the race to deliver the first 400 GB drive, by using more platters with lower data densities. The DeskStar 7K500 simply repeats this strategy: Maxtor and Seagate both have 500 GB drives in the offing, but neither will deliver them before this fall (Q3 2005). Hitachi used existing 100 GB-per-platter technology to trump its rivals, and literally pulled a fast one by using five platters to hit the half teraByte mark.