426:
621:, the number of viable chips produced in a unit time. Chips are produced in batches printed on the surface of a single large silicon wafer, which is cut up and non-working samples are discarded. Fabrication has improved yields over time by using larger wafers, and producing wafers with fewer failures. The lower limit on this process is about $ 1 per completed chip due to packaging and other costs.
36:
494:
in 1957, supplied 3.75 MB for $ 34,500, or $ 9,200 per megabyte. In 1989, a 40 MB hard drive cost $ 1200, or $ 30/MB. And in 2018, 4 Tb drives sold for $ 75, or 1.9¢/GB, an improvement of 1.5 million since 1989 and 520 million since the RAMAC. This is without adjusting for inflation, which
333:
With the notable exception of NAND Flash memory, increasing storage density of a medium typically improves the transfer speed at which that medium can operate. This is most obvious when considering various disk-based media, where the storage elements are spread over the surface of the disk and must
624:
The relationship between information density and cost per bit can be illustrated as follows: a memory chip that is half the physical size means that twice as many units can be produced on the same wafer, thus halving the price of each one. As a comparison, DRAM was first introduced commercially in
486:
In the case of disk-based media, the primary cost is the moving parts inside the drive. This sets a fixed lower limit, which is why the average selling price for both of the major HDD manufacturers has been US$ 45–75 since 2007. That said, the price of high-capacity drives has fallen rapidly, and
356:
Now consider an improvement to the design that doubles the density of the bits by reducing sample length and keeping the same track spacing. This would double the transfer speed because the bits would be passing under the head twice as fast. Early floppy disk interfaces were designed for
122:
Generally, higher density is more desirable, for it allows more data to be stored in the same physical space. Density therefore has a direct relationship to storage capacity of a given medium. Density also generally affects the performance within a particular medium, as well as price.
182:
store data in the magnetic polarization of small patches of the surface coating on a disk. The maximum areal density is defined by the size of the magnetic particles in the surface, as well as the size of the "head" used to read and write the data. In 1956 the first hard drive, the
411:
needed to supply any particular amount of memory decreases, which in turn means less DIMMs overall in any particular computer. This often leads to improved performance as well, as there is less bus traffic. However, this effect is generally not linear.
345:, and the innermost track is about 66 mm long (10.5 mm radius). At 300 rpm the linear speed of the media under the head is thus about 66 mm × 300 rpm = 19800 mm/minute, or 330 mm/s. Along that track the
406:
As fabrication has improved, solid-state memory has improved dramatically in terms of performance. Modern DRAM chips had operational speeds on the order of 10 ns or less. A less obvious effect is that as density improves, the number of
648:, who projected in 2009 that if hard drives were to continue to progress at their then-current pace of about 40% per year, then in 2020 a two-platter, 2.5-inch disk drive would store approximately 40 terabytes (TB) and cost about $ 40.
316:
was successfully used as an experimental data storage medium, but required a DNA synthesizer and DNA microchips for the transcoding. As of 2012, DNA holds the record for highest-density storage medium. In March 2017, scientists at
487:
this is indeed an effect of density. The highest capacity drives use more platters, essentially individual hard drives within the case. As the density increases, the number of platters can be reduced, leading to lower costs.
361:(1,440 KB) floppies in the 1980s. The vast majority of PCs included interfaces designed for high density drives that ran at 500 kbit/s instead. These, too, were completely overwhelmed by newer devices like the
288:, uses an array of many small nanoscopic wires arranged in 3D, each holding numerous bits to improve density. Although exact numbers have not been mentioned, IBM news articles talk of "100 times" increases.
230:
disks are essentially a higher-density CD, using more of the disk surface, smaller pits (0.64 micrometers), and tighter tracks (0.74 micrometers), offering a density of about 2.2 Gbit/in. Single-layer
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399:
is needed for operation, and thus less time is needed to send the required amount of electrical charge into the system. In DRAM, in particular, the amount of charge that needs to be stored in a cell's
203:
introduced a hard drive with a density of 1.34 Tbit/in, more than 600 million times that of the IBM 350. It is expected that current recording technology can "feasibly" scale to at least 5
301:
Other experimental technologies offer even higher densities. Molecular polymer storage has been shown to store 10 Tbit/in. By far the densest type of memory storage experimentally to date is
625:
1971, a 1 kbit part that cost about $ 50 in large batches, or about 5 cents per bit. 64 Mbit parts were common in 1999, which cost about 0.00002 cents per bit (20 microcents/bit).
155:, which must be refreshed multiple times per second, NAND flash is designed to retain its charge state even when not powered up. The highest capacity drives commercially available are the
294:
technologies are also attempting to leapfrog existing systems, but they too have been losing the race, and are estimated to offer 1 Tbit/in as well, with about 250
1053:
436:
226:(CDs) offer a density of about 0.90 Gbit/in, using pits which are 0.83 micrometers long and 0.5 micrometers wide, arranged in tracks spaced 1.6 micrometers apart.
729:
305:. By superimposing images of different wavelengths into the same hologram, in 2009 a Stanford research team achieved a bit density of 35 bit/electron (approximately 3
325:
published a method known as DNA Fountain which allows perfect retrieval of information from a density of 215 petabytes per gram of DNA, 85% of the theoretical limit.
334:
be physically rotated under the "head" in order to be read or written. Higher density means more data moves under the head for any given mechanical movement.
211:(HAMR) and microwave-assisted magnetic recording (MAMR) are under development and are expected to allow increases in magnetic areal density to continue.
57:
44:
349:
are stored at a density of 686 bit/mm, which means that the head sees 686 bit/mm × 330 mm/s = 226,380 bit/s (or 28.3
337:
For example, we can calculate the effective transfer speed for a floppy disc by determining how fast the bits move under the head. A standard 3½-
871:
888:
Parkin, Stuart S. P.; Rettner, Charles; Moriya, Rai; Thomas, Luc (2010-12-24). "Dynamics of
Magnetic Domain Walls Under Their Own Inertia".
387:
One defining electrical property is the resistance of the wires inside the chips. As the cell size decreases, through the improvements in
261:, recorded at the density of 128 bit/in on a half-inch magnetic tape, resulting in the areal density of 256 bit/in. In 2015,
184:
246:, but hard disk drives have since advanced much more quickly and eclipsed optical media in both areal density and capacity per device.
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Although the effect on performance is most obvious on rotating media, similar effects come into play even for solid-state media like
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208:
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448:
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380:. In this case the performance is generally defined by the time it takes for the electrical signals to travel through the
302:
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Storage density also has a strong effect on the price of memory, although in this case, the reasons are not so obvious.
366:
656:
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250 kbit/s transfer speeds, but were rapidly outperformed with the introduction of the "high density" 1.44
49:
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to the chips, and then through the chips to the individual "cells" used to store data (each cell holds one bit).
148:
764:
M. Mallary; et al. (July 2002). "One terabit per square inch perpendicular recording conceptual design".
395:, the resistance is reduced and less power is needed to operate the cells. This, in turn, means that less
342:
322:
222:
store data in small pits in a plastic surface that is then covered with a thin layer of reflective metal.
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Solid-state storage has seen a similar drop in cost per bit. In this case the cost is determined by the
269:, the highest-density production tape shipping in 2015, provides an areal density of 0.84 Gbit/in.
1135:"WD Continues to Widen Gap with Seagate as Average Selling Prices of Hard Disk Drives Continue to Fall"
490:
Hard drives are often measured in terms of cost per bit. For example, the first commercial hard drive,
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996:
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147:. Solid state media data is saved to a pool of NAND flash. NAND itself is made up of what are called
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702:"2014: HDD areal density reaches 1 terabit/sq. in. | The Storage Engine | Computer History Museum"
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system at 1 Tbit/in in 2007 but development appears to be moribund. A newer IBM technology,
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and
Fujifilm claimed a new record for the magnetic tape areal density of 123 Gbit/in, while
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948:"New Method Of Self-assembling Nanoscale Elements Could Transform Data Storage Industry"
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A number of technologies are attempting to surpass the densities of existing media.
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disks offer densities around 7.5 Gbit/in and 12.5 Gbit/in, respectively.
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1054:"This Speck of DNA Contains a Movie, a Computer Virus, and an Amazon Gift Card"
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298:/in being the best demonstrated to date for non-quantum holography systems.
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The lead should conttain a summary of each major section of the article
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Exadrive© DC series drives, these drives come in capacities ranging 16
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232:
112:
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242:
When introduced in 1982 CDs had considerably higher densities than
1080:"DNA Fountain enables a robust and efficient storage architecture"
88:
800:"Seagate Plans To HAMR WD's MAMR; 20TB HDDs With Lasers Inbound"
408:
377:
338:
152:
419:
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143:. They are the latest form of mass produced storage and rival
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of all important aspects of the article. The reason given is:
29:
365:, which were forced to use higher-speed interfaces such as
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IBM claims new areal density record with 220TB tape tech
444:
309:/in) using electron microscopes and a copper medium.
985:"Next-Generation Digital Information Storage in DNA"
1150:
Average selling prices of hard disk drives in $ USD
1040:Next-Generation Digital Information Storage in DNA
825:
195:. Since then, the increase in density has matched
983:Church, G. M.; Gao, Y.; Kosuri, S. (2012-09-28).
171:has a 6:1 space saving ratio over a nearline HDD
869:HP LTO-6 Media Metal Particle and Barium Ferrite
1078:Erlich, Yaniv; Zielinski, Dina (2 March 2017).
966:"Reading the fine print takes on a new meaning"
495:increased prices nine-fold from 1956 to 2018.
207:/in in the near future. New technologies like
433:The examples and perspective in this article
8:
199:, reaching 1 Tbit/in in 2014. In 2015,
167:. Nimbus states that for its size the 100TB
95:. There are three types of density: length (
83:is a measure of the quantity of information
723:
721:
1008:
471:Learn how and when to remove this message
497:
151:. Unlike the transistor designs used in
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828:Magnetic Recording, The First 100 Years
668:
56:Please consider expanding the lead to
7:
254:The first magnetic tape drive, the
25:
499:Hard drive cost per GB over time
403:also directly affects this time.
280:IBM aimed to commercialize their
730:"Tech Talk on HDD Areal Density"
424:
209:heat-assisted magnetic recording
187:, had an areal density of 2,000
34:
48:may be too short to adequately
766:IEEE Transactions on Magnetics
341:floppy disk spins at 300
87:that can be stored on a given
58:provide an accessible overview
1:
303:electronic quantum holography
1133:Shilov, Anton (2013-10-29).
824:Daniel; et al. (1999).
728:Re, Mark (August 25, 2015).
859:The Register, 10 April 2015
657:Shingled magnetic recording
447:, discuss the issue on the
1210:
874:December 22, 2015, at the
139:use flash memory to store
786:10.1109/tmag.2002.1017762
389:semiconductor fabrication
149:floating gate transistors
27:Computer storage measure
1104:10.1126/science.aaj2038
1042:Science, September 2012
1010:10.1126/science.1226355
910:10.1126/science.1197468
706:www.computerhistory.org
93:computer storage medium
1194:Computer storage media
832:. IEEE Press. p.
329:Effects on performance
323:New York Genome Center
127:Storage device classes
453:create a new article
445:improve this article
435:may not represent a
1096:2017Sci...355..950E
1001:2012Sci...337.1628C
902:2010Sci...330.1810T
896:(6012): 1810–1813.
778:2002ITM....38.1719M
500:
319:Columbia University
292:Holographic storage
250:Magnetic tape media
175:Magnetic disk media
145:magnetic disk media
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215:Optical disc media
141:non-volatile media
137:Solid state drives
117:volumetric density
1090:(6328): 950–954.
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527:$ 9.2 million/GB
481:
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455:, as appropriate.
132:Solid state media
111:), or in a given
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282:Millipede memory
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180:Hard disk drives
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1141:. xbitlabs.com
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804:Tom's Hardware
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1058:The Atlantic
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952:ScienceDaily
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806:. 2017-11-03
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748:. Retrieved
741:the original
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709:. Retrieved
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685:. Retrieved
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541:$ 30,000/GB
489:
485:
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467:
461:January 2014
458:
434:
405:
391:that led to
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382:computer bus
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185:IBM 350
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47:
45:lead section
1170:iiasa.ac.at
681:Nimbus Data
677:"ExaDrive®"
646:Mark Kryder
611:$ 0.022/GB
597:$ 0.019/GB
583:$ 0.035/GB
492:IBM's RAMAC
393:Moore's Law
197:Moore's Law
157:Nimbus Data
1183:Categories
1145:2014-08-11
1052:Yong, Ed.
810:2018-05-27
750:2018-05-27
711:2018-05-27
687:2020-11-16
664:References
1019:0036-8075
918:1095-9203
555:$ 850/GB
524:$ 34,500
507:capacity
449:talk page
401:capacitor
374:Flash RAM
312:In 2012,
69:June 2024
50:summarize
1166:"DRAM 3"
1139:xbitlabs
1120:13470340
1112:28254941
1027:22903519
934:30606800
926:21205666
872:Archived
640:Bit cell
629:See also
538:$ 1,200
521:3.75 MB
443:You may
321:and the
307:exabytes
273:Research
259:Uniservo
1189:Density
1092:Bibcode
1084:Science
1063:3 March
997:Bibcode
989:Science
898:Bibcode
890:Science
774:Bibcode
737:Seagate
569:$ 1/GB
563:250 GB
237:Blu-ray
201:Seagate
105:surface
81:Density
1118:
1110:
1035:934617
1033:
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840:
608:$ 175
566:$ 250
552:$ 850
535:40 MB
513:$ /GB
363:LS-120
256:Univac
233:HD DVD
163:to 100
113:volume
1116:S2CID
1031:S2CID
930:S2CID
744:(PDF)
733:(PDF)
659:(SMR)
619:yield
605:8 TB
602:2023
594:$ 75
591:4 TB
588:2018
580:$ 70
577:2 TB
574:2011
560:2004
549:1 GB
546:1995
532:1989
518:1957
510:cost
504:date
451:, or
409:DIMMs
353:/s).
267:LTO-6
101:track
99:) of
91:of a
1108:PMID
1065:2017
1023:PMID
1015:ISSN
922:PMID
914:ISSN
838:ISBN
378:DRAM
347:bits
339:inch
235:and
205:Tbit
153:DRAM
85:bits
1100:doi
1088:355
1005:doi
993:337
906:doi
894:330
834:254
782:doi
376:or
367:IDE
343:rpm
314:DNA
263:IBM
228:DVD
189:bit
169:SSD
119:).
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1157:^
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1021:.
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1003:.
991:.
987:.
968:.
950:.
928:.
920:.
912:.
904:.
892:.
836:.
802:.
780:.
770:38
768:.
735:.
720:^
704:.
679:.
369:.
359:MB
351:KB
296:GB
193:in
165:TB
161:TB
1172:.
1122:.
1102::
1094::
1067:.
1037:.
1007::
999::
954:.
936:.
908::
900::
846:.
813:.
788:.
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776::
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714:.
690:.
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463:)
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441:.
191:/
115:(
107:(
71:)
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54:.
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