Perpendicular recording
magnetic disk drive recording technology
Perpendicular recording (or perpendicular magnetic recording, PMR), also known as conventional magnetic recording (CMR), is a technology for data recording on magnetic media, particularly hard disks. It was first proven advantageous in 1976 by Shun-ichi Iwasaki, then professor of the Tohoku University in Japan, and first commercially implemented in 2005. The first industry-standard demonstration showing unprecedented advantage of PMR over longitudinal magnetic recording (LMR) at nanoscale dimensions was made in 1998 at IBM Almaden Research Center in collaboration with researchers of Data Storage Systems Center (DSSC) – a National Science Foundation (NSF) Engineering Research Center (ERCs) at Carnegie Mellon University (CMU).
Advantages
Perpendicular recording can deliver more than three times the storage density of traditional longitudinal recording. In 1986, Maxell announced a floppy disk using perpendicular recording that could store 100 kB per inch (39 kB/cm). Perpendicular recording was later used by Toshiba in 3.5" floppy disks in 1989 to permit 2.88 MB of capacity (ED or extra-high density), but they failed to succeed in the marketplace. Since about 2005, the technology has come into use for hard disk drives. Hard disk technology with longitudinal recording has an estimated limit of 100 to 200 gigabit per square inch (16 to 31 Gb/cm2) due to the superparamagnetic effect, though this estimate is constantly changing. Perpendicular recording was predicted in 2007 to allow information densities of up to around 1,000 Gbit/in2 (160 Gb/cm2). As of August 2010, drives with densities of 667 Gb/in2 (103.4 Gb/cm2) were available commercially.
Begin with the source’s own compact description: “Perpendicular recording” is magnetic disk drive recording technology. The dossier treats that line as a proposition to test through Perpendicular, recording and magnetic, not as a finished interpretation.
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The phrase “magnetic disk drive recording technology” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Object files, edition statements, performance records and contemporary criticism preserve different stages of the work’s history. The source revision retrieved here is dated Apr 16, 2026. The linked authority identifier is Q1755844. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1976, 2005, 1998 and 1986.
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This entry incorporates text from “Perpendicular recording” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.