{
  "slug": "pmr",
  "term": "Perpendicular magnetic recording (PMR)",
  "aliases": [
    "perpendicular recording"
  ],
  "definition": "A magnetic recording orientation where bits stand perpendicular to the platter, enabling higher areal density than longitudinal recording.",
  "note": "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.",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "cmr",
    "smr",
    "hamr",
    "mamr",
    "longitudinal-recording"
  ],
  "supersedes": [
    "longitudinal-recording"
  ],
  "supersededBy": [],
  "firstSeen": {
    "date": "2005",
    "citationIds": [
      "c1"
    ]
  },
  "lastSeen": null,
  "citations": [
    {
      "id": "c1",
      "title": "Perpendicular recording",
      "url": "https://en.wikipedia.org/wiki/Perpendicular_recording",
      "accessed": "2026-03-26"
    },
    {
      "id": "n2",
      "title": "Seagate — HAMR technology paper TP707 (PMR context and density limits)",
      "url": "https://www.seagate.com/content/dam/seagate/migrated-assets/www-content/ti-dm/tech-insights/en-us/docs/TP707-1-1712US_HAMR.pdf",
      "accessed": "2026-10-07"
    },
    {
      "id": "n3",
      "title": "Seagate — Heat-Assisted Magnetic Recording (HAMR) overview",
      "url": "https://www.seagate.com/innovation/hamr/",
      "accessed": "2026-10-07"
    }
  ]
}