What is PMR?
Perpendicular Magnetic Recording (PMR) is the technology employed for the new generation of hard disk media. Since its conception in 1957, media makers have been using Longitudinal Magnetic Recording (LMR) in their media. However, increasing demand in storage capacities has pushed this methodology to its limits.
To increase media recording capacity (GB/p), an increasing amount of magnetic bits must be compacted on to the media surface. Since the media dimensions do not change, magnetic crystals have to be shrunk and placed in very close proximity to accommodate media storage's exponential growth. Crystals placed in such extreme proximity start to become thermally unstable thus affecting the media performance (data integrity). This phenomena is known as superparamagnetism.
PMR technology helps to solve this problem. In PMR magnetic bits are aligned perpendicular to the plane of the media. This action will allow for more bits to be placed within the same area. Also, PMR will be tapping magnetic field from pole tips instead of fringe fields (weaker signal) as in LMR.
Hence, PMR technology has the potential to double the storage capacities of HDDs in the market presently.