Western Digital Perpendicular Magnetic Recording (PMR) - WD Addresses Hard Drive Capacity Challenge with PMR Technol free download

File name Perpendicular Magnetic Recording (PMR) - WD Addresses Hard Drive Capacity Challenge with PMR Technol

Perpendicular Magnetic Recording (PMR) WD Addresses Hard Drive Capacity Challenge with PMR Technology The Perpendicular Recording Solution F or decades, the hard drive industry has focused almost exclusively on a method called longitudinal magnetic recording to record data on hard drives. In longitudinal In longitudinal recording, as the bits become smaller and closer together, they experience an increasing demagnetizing field, recording, the magnetization of each data bit (i.e., the binary much like two bar magnets that are placed end-to-end repel one digit 0 or 1) is aligned horizontally, parallel to the disk that spins another. Coercivity must be increased to counteract the inside the hard drive. demagnetization to keep the bits stable under thermal In perpendicular magnetic recording (PMR), the magnetization fluctuations; otherwise data corruption may occur over time. of each data bit is aligned vertically to the spinning disk, Higher media coercivity has pushed the recording head write providing the ability to store more data on a given disk than is field to the limit of known materials. possible with conventional longitudinal recording. PMR thus In perpendicular recording, the adjacent bits attract instead of provides a platform for future expansion of hard drive densities. repel (as with bar magnets placed side by side,) creating more WD will implement PMR technology in calendar year 2006. thermally stable bits. In addition, the media contains a magnetically soft underlayer (SUL) beneath the recording layer. The Storage Capacity Challenge