A graphic demonstrating the difference between conventional drives and patterned media drives.
In conventional drives, the bits, which store data in a drive and are magnetized in a particular direction, touch each other. Reducing the size of the magnetic grains inside the bits and the bits could lead to bit flipping, or data corruption.
In patterned media, the bits are isolated from each other and smaller, reducing cross talk and data corruption. The dot pattern, however, needs to be drawn through lithography, which is often expensive.
Hitachi Global Storage Technologies