Perpendicular magnetic recording (PMR)
A magnetic recording orientation where bits stand perpendicular to the platter, enabling higher areal density than longitudinal recording.
Perpendicular Magnetic Recording orients each bit’s magnetization normal to the platter plane, typically on granular CoCrPt media above a soft magnetic underlayer that strengthens the write field in the media “gap.” That geometry enabled smaller grains and higher areal density than longitudinal recording. PMR is the magnetic physics layer; CMR/SMR describe whether tracks overlap. Seagate’s HAMR technical literature frames PMR as approaching roughly 1 Tb/in² practical limits before heat- or microwave-assisted writers are needed on high-coercivity media. Datasheets may say “perpendicular,” “PMR,” or simply list “CMR” for product behavior on PMR media.
Relations
- related
- cmr, smr, hamr, mamr, longitudinal-recording
- supersedes
- longitudinal-recording