fbpx
Wikipedia

Perpendicular recording

April 12, 2024

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)[1] – a National Science Foundation (NSF) Engineering Research Center (ERCs) at Carnegie Mellon University (CMU).[2]

Advantages edit

Perpendicular recording can deliver more than three times the storage density of traditional longitudinal recording.[3] In 1986, Maxell announced a floppy disk using perpendicular recording that could store 100 kB per inch (39 kB/cm).[4] 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 Gbit/cm2).[5] As of August 2010, drives with densities of 667 Gb/in2 (103.4 Gb/cm2) were available commercially. In 2016 the commercially available density was at least 1,300 Gb/in2 (200 Gb/cm2).[6] In late 2021 the Seagate disk with the highest density was a consumer-targeted 2.5" BarraCuda. It used 1,307 Gb/in2 (202.6 Gb/cm2)[7] density. Other disks from the manufacturer used 1,155 Gb/in2 (179.0 Gb/cm2) and 1,028 Gb/in2 (159.3 Gb/cm2).

Technology edit

 
Diagram of perpendicular recording. Note how the magnetic flux travels through the second layer of the platter.

The main challenge in designing magnetic information storage media is to retain the magnetization of the medium despite thermal fluctuations caused by the superparamagnetic limit. If the thermal energy is too high, there may be enough energy to reverse the magnetization in a region of the medium, destroying the data stored there. The energy required to reverse the magnetization of a magnetic region is the product of the size of the magnetic region and the uniaxial anisotropy constant Ku, which is in turn related to the magnetic coercivity of the material. The larger the magnetic region is and the higher the magnetic coercivity of the material, the more stable the medium is. Conversely, there is a minimum stable size for a magnetic region at a given temperature and coercivity. If it is any smaller it is likely to be spontaneously de-magnetized by local thermal fluctuations. Perpendicular recording uses higher coercivity materials because the head's write field penetrates the medium more efficiently in the perpendicular geometry.

The popular explanation for the advantage of perpendicular recording is that it achieves higher storage densities by aligning the poles of the magnetic elements, which represent bits, perpendicularly to the surface of the disk platter, as shown in the illustration. In this not-quite-accurate explanation, aligning the bits in this manner takes less platter area than what would have been required had they been placed longitudinally. This means cells can be placed closer together on the platter, thus increasing the number of magnetic elements that can be stored in a given area.

 
Trailing shield head with granular media. This head design provides higher field gradients and more advantageous field angles for perpendicular recording.[8]

The true picture is a bit more complex. Perpendicular recording does indeed penetrate more deeply into the magnetic storage medium, thereby allowing a closer bit spacing without losing overall bit volume.[8] However, the main density advantage comes from the use of a magnetically "stiffer" (higher coercivity) material as the storage medium.

This is possible because in a perpendicular arrangement the magnetic flux is guided through a magnetically soft (and relatively thick) underlayer beneath the "hard" data storage layer (considerably complicating and thickening the total disk structure). This underlayer can be thought of as part of the write head, completing a magnetic circuit which transects the data storage layer. Having more of the magnetic flux penetrate the data storage layer makes the write head more efficient than a longitudinal head, produces a stronger write field gradient, and thereby allows the use of the higher coercivity magnetic storage medium.

In the early 2000s, three important factors came together which allowed perpendicular recording to exceed the capabilities of longitudinal recording and led to commercial success.[9] First, the development of media with an oxide-segregant exchange-break between grains.[10] Second, the use of a thin 'cap' on the media to control the level of exchange-coupling between grains[11] and to enhance propagation of switching through the thickness of the medium.[12] Third, the introduction of the trailing-shield head invented by Michael Mallary. This head offered higher field gradients and more favorable field angles than a simple pole head.[13]

Implementations edit

Vertimag Systems Corporation, founded by Professor Jack Judy of the University of Minnesota. As a colleague of Iwasaki, created the first perpendicular disk drives, heads and disks in 1984. 5 MB removable floppy drives were demonstrated in IBM PCs to major computer manufacturers. Vertimag went out of business during the PC crash of 1985.

Toshiba produced the first commercially available disk drive (1.8") using this technology in 2005.[14] Shortly thereafter in January 2006, Seagate Technology began shipping its first laptop sized 2.5-inch (64 mm) hard drive using perpendicular recording technology, the Seagate Momentus 5400.3. Seagate also announced at that time that the majority of its hard disk storage devices would utilize the new technology by the end of 2006.

In April 2006, Seagate began shipping the first 3.5 inch perpendicular recording hard drive, the Cheetah 15K.5, with up to 300GB storage, running at 15,000 rpm and claim to have 30% better performance than their predecessors with a data rate of 73–125 Mbyte/s.

In April 2006, Seagate announced the Barracuda 7200.10, a series of 3.5-inch (89 mm) HDDs utilizing perpendicular recording with a maximum capacity of 750 GB. Drives began shipping in late April 2006.

Hitachi announced a 20 GB Microdrive. Hitachi's first laptop drive (2.5-inch) based on perpendicular recording became available in mid-2006, featuring a maximum capacity of 160 GB.

In June 2006, Toshiba announced a 2.5-inch (64 mm) hard drive of 200-GB capacity with mass production starting in August, effectively raising the standard of mobile storage capacity.

In July 2006, Western Digital announced volume production of its WD Scorpio 2.5-inch (64 mm) hard drives using WD-designed and manufactured perpendicular magnetic recording (PMR) technology to achieve 80 GB-per-platter density.

In August 2006 Fujitsu extended its 2.5-inch (64 mm) lineup to include SATA models utilizing perpendicular recording, offering up to 160GB capacity.

In December 2006 Toshiba said its new 100GB two-platter HDD is based on perpendicular magnetic recording (PMR) and was designed in the "short" 1.8-inch form factor.[15]

In December 2006 Fujitsu announced its MHX2300BT series of 2.5-inch (64 mm) hard disk drives, with capacities of 250 and 300 GB.

In January 2007 Hitachi announced the first 1-terabyte hard drive[16] using the technology, which they then delivered in April 2007.[17]

In July 2008 Seagate Technology announced a 1.5 terabyte SATA hard drive using PMR technology.

In January 2009 Western Digital announced the first 2.0 terabyte SATA hard drive using PMR technology.

In February 2009 Seagate Technology announced the first 7,200rpm 2.0 terabyte SATA hard drive using PMR technology with choice of SATA 2 or SAS 2.0 interface.

See also edit

References edit

  • S.N. Piramanayagam, J. Appl. Phys. 102, 011301 (2007).
  1. ^ https://www.dssc.ece.cmu.edu/
  2. ^ S. Khizroev, M. Kryder, Y. Ikeda, K. Rubin, P. Arnett, M. Best, D. A. Thompson, "Recording heads with trackwidths suitable for 100 Gbit/in2 density, "IEEE Trans. Magn., 35 (5), 2544–6 (1999)[1] 14 December 2013 at the Wayback Machine
  3. ^ Merritt, Rick (26 September 2005). "Hard drives go perpendicular". EE Times. from the original on 5 April 2023. Retrieved 26 November 2023.
  4. ^ Bateman, Selby (March 1986). "The Future of Mass Storage". COMPUTE!. No. 70. COMPUTE! Publications. p. 23. Retrieved 7 October 2018.
  5. ^ "Hitachi News Release – Hitachi achieves nanotechnology milestone for quadrupling terabyte hard drive". 15 October 2007. from the original on 28 April 2017. Retrieved 20 February 2008.
  6. ^ "Seagate Barracuda Compute SATA 2.5" Product Manual, October 2016" (PDF). Retrieved 9 May 2021.
  7. ^ "BarraCuda 4TB, 5TB (2.5) Product Manual" (PDF). 30 September 2020. Retrieved 29 October 2021.
  8. ^ a b Wood, Roger (March 2009). "Future hard disk drive systems". Journal of Magnetism and Magnetic Materials. 321 (6): 555–561. Bibcode:2009JMMM..321..555W. doi:10.1016/j.jmmm.2008.07.027.
  9. ^ "2005: Perpendicular Magnetic Recording arrives". Computer History Museum, Data Storage Milestone. Retrieved 10 March 2024.
  10. ^ "Magnetic Recording Media", 1.5.3 Encyclopedia of Physical Science and Technology (Third Edition), 2003
  11. ^ Sonobe, Y.; Tham, K.K.; Umezawa, T.; Takasu, C.; Dumaya, J.A.; Leo, P.Y. (2006). "Effect of continuous layer in CGC perpendicular recording media". Journal of Magnetism and Magnetic Materials. 303 (2): 292–295. Bibcode:2006JMMM..303..292S. doi:10.1016/j.jmmm.2006.01.164.
  12. ^ Victora, R.H.; Shen, X. (2005). "Exchange coupled composite media for perpendicular magnetic recording". IEEE Transactions on Magnetics. 41 (10): 2828–2833. Bibcode:2005ITM....41.2828V. doi:10.1109/TMAG.2005.855263.
  13. ^ "Perpendicular Magnetic Recording Technology" white paper, HGST Nov 2007
  14. ^ "First Perpendicular Recording HDD – Toshiba Press Release". from the original on 14 April 2009. Retrieved 16 March 2008.
  15. ^ "Briefly: Foxconn to build 1.5m MBPs; 100GB iPod drive". AppleInsider. from the original on 8 December 2006. Retrieved 6 December 2006.
  16. ^ "Hitachi Introduces 1-Terabyte Hard Drive". PC World. from the original on 12 January 2007. Retrieved 10 January 2007.
  17. ^ "Hitachi gets its one terabyte Deskstar 7K1000 drives out the door". Engadget. from the original on 17 September 2017. Retrieved 8 September 2017.

External links edit

  • A Flash animation and song explaining perpendicular recording from Hitachi Research
  • Perpendicular Magnetic Recording (Hardcover) by Sakhrat Khizroev, Dmitri Litvinov: ISBN 1-4020-2662-5

April 12, 2024
perpendicular, recording, perpendicular, magnetic, recording, also, known, conventional, magnetic, recording, technology, data, recording, magnetic, media, particularly, hard, disks, first, proven, advantageous, 1976, shun, ichi, iwasaki, then, professor, toho. 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 1 a National Science Foundation NSF Engineering Research Center ERCs at Carnegie Mellon University CMU 2 Contents 1 Advantages 2 Technology 3 Implementations 4 See also 5 References 6 External linksAdvantages editPerpendicular recording can deliver more than three times the storage density of traditional longitudinal recording 3 In 1986 Maxell announced a floppy disk using perpendicular recording that could store 100 kB per inch 39 kB cm 4 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 Gbit cm2 5 As of August 2010 update drives with densities of 667 Gb in2 103 4 Gb cm2 were available commercially In 2016 the commercially available density was at least 1 300 Gb in2 200 Gb cm2 6 In late 2021 the Seagate disk with the highest density was a consumer targeted 2 5 BarraCuda It used 1 307 Gb in2 202 6 Gb cm2 7 density Other disks from the manufacturer used 1 155 Gb in2 179 0 Gb cm2 and 1 028 Gb in2 159 3 Gb cm2 Technology edit nbsp Diagram of perpendicular recording Note how the magnetic flux travels through the second layer of the platter The main challenge in designing magnetic information storage media is to retain the magnetization of the medium despite thermal fluctuations caused by the superparamagnetic limit If the thermal energy is too high there may be enough energy to reverse the magnetization in a region of the medium destroying the data stored there The energy required to reverse the magnetization of a magnetic region is the product of the size of the magnetic region and the uniaxial anisotropy constant Ku which is in turn related to the magnetic coercivity of the material The larger the magnetic region is and the higher the magnetic coercivity of the material the more stable the medium is Conversely there is a minimum stable size for a magnetic region at a given temperature and coercivity If it is any smaller it is likely to be spontaneously de magnetized by local thermal fluctuations Perpendicular recording uses higher coercivity materials because the head s write field penetrates the medium more efficiently in the perpendicular geometry The popular explanation for the advantage of perpendicular recording is that it achieves higher storage densities by aligning the poles of the magnetic elements which represent bits perpendicularly to the surface of the disk platter as shown in the illustration In this not quite accurate explanation aligning the bits in this manner takes less platter area than what would have been required had they been placed longitudinally This means cells can be placed closer together on the platter thus increasing the number of magnetic elements that can be stored in a given area nbsp Trailing shield head with granular media This head design provides higher field gradients and more advantageous field angles for perpendicular recording 8 The true picture is a bit more complex Perpendicular recording does indeed penetrate more deeply into the magnetic storage medium thereby allowing a closer bit spacing without losing overall bit volume 8 However the main density advantage comes from the use of a magnetically stiffer higher coercivity material as the storage medium This is possible because in a perpendicular arrangement the magnetic flux is guided through a magnetically soft and relatively thick underlayer beneath the hard data storage layer considerably complicating and thickening the total disk structure This underlayer can be thought of as part of the write head completing a magnetic circuit which transects the data storage layer Having more of the magnetic flux penetrate the data storage layer makes the write head more efficient than a longitudinal head produces a stronger write field gradient and thereby allows the use of the higher coercivity magnetic storage medium In the early 2000s three important factors came together which allowed perpendicular recording to exceed the capabilities of longitudinal recording and led to commercial success 9 First the development of media with an oxide segregant exchange break between grains 10 Second the use of a thin cap on the media to control the level of exchange coupling between grains 11 and to enhance propagation of switching through the thickness of the medium 12 Third the introduction of the trailing shield head invented by Michael Mallary This head offered higher field gradients and more favorable field angles than a simple pole head 13 Implementations editVertimag Systems Corporation founded by Professor Jack Judy of the University of Minnesota As a colleague of Iwasaki created the first perpendicular disk drives heads and disks in 1984 5 MB removable floppy drives were demonstrated in IBM PCs to major computer manufacturers Vertimag went out of business during the PC crash of 1985 Toshiba produced the first commercially available disk drive 1 8 using this technology in 2005 14 Shortly thereafter in January 2006 Seagate Technology began shipping its first laptop sized 2 5 inch 64 mm hard drive using perpendicular recording technology the Seagate Momentus 5400 3 Seagate also announced at that time that the majority of its hard disk storage devices would utilize the new technology by the end of 2006 In April 2006 Seagate began shipping the first 3 5 inch perpendicular recording hard drive the Cheetah 15K 5 with up to 300GB storage running at 15 000 rpm and claim to have 30 better performance than their predecessors with a data rate of 73 125 Mbyte s In April 2006 Seagate announced the Barracuda 7200 10 a series of 3 5 inch 89 mm HDDs utilizing perpendicular recording with a maximum capacity of 750 GB Drives began shipping in late April 2006 Hitachi announced a 20 GB Microdrive Hitachi s first laptop drive 2 5 inch based on perpendicular recording became available in mid 2006 featuring a maximum capacity of 160 GB In June 2006 Toshiba announced a 2 5 inch 64 mm hard drive of 200 GB capacity with mass production starting in August effectively raising the standard of mobile storage capacity In July 2006 Western Digital announced volume production of its WD Scorpio 2 5 inch 64 mm hard drives using WD designed and manufactured perpendicular magnetic recording PMR technology to achieve 80 GB per platter density In August 2006 Fujitsu extended its 2 5 inch 64 mm lineup to include SATA models utilizing perpendicular recording offering up to 160GB capacity In December 2006 Toshiba said its new 100GB two platter HDD is based on perpendicular magnetic recording PMR and was designed in the short 1 8 inch form factor 15 In December 2006 Fujitsu announced its MHX2300BT series of 2 5 inch 64 mm hard disk drives with capacities of 250 and 300 GB In January 2007 Hitachi announced the first 1 terabyte hard drive 16 using the technology which they then delivered in April 2007 17 In July 2008 Seagate Technology announced a 1 5 terabyte SATA hard drive using PMR technology In January 2009 Western Digital announced the first 2 0 terabyte SATA hard drive using PMR technology In February 2009 Seagate Technology announced the first 7 200rpm 2 0 terabyte SATA hard drive using PMR technology with choice of SATA 2 or SAS 2 0 interface See also editExchange spring media Heat assisted magnetic recording HAMR Shingled magnetic recording SMR References editS N Piramanayagam J Appl Phys 102 011301 2007 https www dssc ece cmu edu S Khizroev M Kryder Y Ikeda K Rubin P Arnett M Best D A Thompson Recording heads with trackwidths suitable for 100 Gbit in2 density IEEE Trans Magn 35 5 2544 6 1999 1 Archived 14 December 2013 at the Wayback Machine Merritt Rick 26 September 2005 Hard drives go perpendicular EE Times Archived from the original on 5 April 2023 Retrieved 26 November 2023 Bateman Selby March 1986 The Future of Mass Storage COMPUTE No 70 COMPUTE Publications p 23 Retrieved 7 October 2018 Hitachi News Release Hitachi achieves nanotechnology milestone for quadrupling terabyte hard drive 15 October 2007 Archived from the original on 28 April 2017 Retrieved 20 February 2008 Seagate Barracuda Compute SATA 2 5 Product Manual October 2016 PDF Retrieved 9 May 2021 BarraCuda 4TB 5TB 2 5 Product Manual PDF 30 September 2020 Retrieved 29 October 2021 a b Wood Roger March 2009 Future hard disk drive systems Journal of Magnetism and Magnetic Materials 321 6 555 561 Bibcode 2009JMMM 321 555W doi 10 1016 j jmmm 2008 07 027 2005 Perpendicular Magnetic Recording arrives Computer History Museum Data Storage Milestone Retrieved 10 March 2024 Magnetic Recording Media 1 5 3 Encyclopedia of Physical Science and Technology Third Edition 2003 Sonobe Y Tham K K Umezawa T Takasu C Dumaya J A Leo P Y 2006 Effect of continuous layer in CGC perpendicular recording media Journal of Magnetism and Magnetic Materials 303 2 292 295 Bibcode 2006JMMM 303 292S doi 10 1016 j jmmm 2006 01 164 Victora R H Shen X 2005 Exchange coupled composite media for perpendicular magnetic recording IEEE Transactions on Magnetics 41 10 2828 2833 Bibcode 2005ITM 41 2828V doi 10 1109 TMAG 2005 855263 Perpendicular Magnetic Recording Technology white paper HGST Nov 2007 First Perpendicular Recording HDD Toshiba Press Release Archived from the original on 14 April 2009 Retrieved 16 March 2008 Briefly Foxconn to build 1 5m MBPs 100GB iPod drive AppleInsider Archived from the original on 8 December 2006 Retrieved 6 December 2006 Hitachi Introduces 1 Terabyte Hard Drive PC World Archived from the original on 12 January 2007 Retrieved 10 January 2007 Hitachi gets its one terabyte Deskstar 7K1000 drives out the door Engadget Archived from the original on 17 September 2017 Retrieved 8 September 2017 External links edit Get Perpendicular A Flash animation and song explaining perpendicular recording from Hitachi Research Perpendicular Magnetic Recording Hardcover by Sakhrat Khizroev Dmitri Litvinov ISBN 1 4020 2662 5 Retrieved from https en wikipedia org w index php title Perpendicular recording amp oldid 1214553007, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.