Question: What is the world's largest hard drive?

History of hard disk drives


In 1953, IBM recognized the immediate application for what it termed a "Random Access File" having high capacity and rapid random access at a relatively low cost.[1] After considering technologies such as wire matrices, rod arrays, drums, drum arrays, etc.,[1] the engineers at IBM's San Jose California laboratory invented the hard disk drive.[2] The disk drive created a new level in the computer data hierarchy, then termed Random Access Storage but today known as secondary storage, less expensive and slower than main memory (then typically drums) but faster and more expensive than tape drives.[3]
The commercial usage of hard disk drives (HDD) began in 1957, with the shipment of a production IBM 305 RAMAC system including IBM Model 350 disk storage.[4]  issued March 24, 1970, and arising from the IBM RAMAC program is generally considered to be the fundamental patent for disk drives.[5]
Each generation of disk drives replaced larger, more sensitive and more cumbersome devices. The earliest drives were usable only in the protected environment of a data center. Later generations progressively reached factories, offices and homes, eventually becoming ubiquitous.
Disk media diameter was initially 24 inches in diameter, but over time it has been reduced to today's 3.5-inch and 2.5-inch standard sizes. Drives with the larger 24-inch- and 14-inch-diameter media were typically mounted in standalone boxes (resembling washing machines) or large equipment rack enclosures. Individual drives often required high-current AC power due to the large motors required to spin the large disks. Drives with smaller media generally conformed to de facto standard form factors.
The capacity of hard drives has grown exponentially over time. When hard drives became available for personal computers, they offered 5-megabyte capacity. During the mid-1990s the typical hard disk drive for a PC had a capacity of about 1 gigabyte.[6] As of January 2019, desktop hard disk drives typically had a capacity of 1 to 6 terabytes, with the largest-capacity drives reaching 15 terabytes.
Unit production peaked in 2010 at about 650 million units and has been in a slow decline since then.
1950s–1970s

The IBM 350 Disk File was developed under the code-name RAMAC by an IBM San Jose team led by Reynold Johnson. It was announced in 1956 with the then new IBM 305 RAMAC computer.[7] A variant, the IBM 355 Disk File, was simultaneously announced with the IBM RAM 650 computer,[8] an enhancement to the IBM 650.
The IBM 350 drive had fifty 24-inch (0.6m) platters, with a total capacity of five million 6-bit characters (3.75 megabytes).[9] A single head assembly having two heads was used for access to all the platters, yielding an average access time of just under 1 second.
The RAMAC disk drive created a new level in the computer data hierarchy, today known as secondary storage, less expensive and slower than main memory (then typically core or drum) but faster and more expensive than tape drives.[3]  Subsequently there was a period of about 20 years in which other technologies competed with disks in the secondary storage marketplace, for example tape strips, e.g., NCR CRAM, tape cartridges, e.g., IBM 3850, and drums, e.g., Burroughs B430, UNIVAC FASTRAND, but all ultimately were displaced by HDDs.  Today SSDs compete with HDDs in the marketplace.
The IBM 1301 Disk Storage Unit,[10] announced in 1961, introduced the usage of heads having self-acting air bearings (self-flying heads) with one head per each surface of the disks.
Also in 1961, Bryant Computer Products introduced its 4000 series disk drives. These massive units stood 52 inches (1.3m) tall, 70 inches (1.8m) wide, and had up to 26 platters, each 39 inches (0.99m) in diameter, rotating at up to 1,200 rpm. Access times were from 50 to 205 milliseconds (ms). The drive's total capacity, depending on the number of platters installed, was up to 205,377,600 bytes (205MB).[11][12]

The first disk drive to use removable media was the IBM 1311 drive.  It was introduced in 1962 using the IBM 1316 disk pack to store two million characters.  It was followed by the IBM 2311 (1964) using the IBM 1316 disk pack to store 5 megabyte, IBM 2314 (1965) using the IBM 2316 disk pack to store 29 megabytes, the IBM 3330 using 3336 disk packs to store 100 megabytes and the 3330-11 using the 3336-11 to store 200 megabytes.Memorex in 1968 shipped the first HDD, the Memorex 630, plug compatible to an IBM model 2311 marking the beginning of independent competition (Plug Compatible Manufacturers or PCMs) for HDDs attached to IBM systems.  It was followed in 1969 by the Memorex 660, an IBM 2314 compatible, which was OEM'ed to DEC and resold as the RP02.
In 1973, IBM introduced the IBM 3340 "Winchester" disk drive and the 3348 data module, the first significant commercial use of low mass and low load heads with lubricated platters and the last IBM disk drive with removable media. This technology and its derivatives remained the standard through 2011. Project head Kenneth Haughton named it after the Winchester 30-30 rifle because it was planned to have two 30MB spindles; however, the actual product shipped with two spindles for data modules of either 35MB or 70MB.[13] The name 'Winchester' and some derivatives are still common in some non-English speaking countries to generally refer to any hard disks (e.g. Hungary, Russia).
Also in 1973, Control Data Corporation introduced the first of its series of SMD disk drives using conventional disk pack technology. The SMD family became the predominant disk drive in the minicomputer market into the 1980s.
Smaller diameter media came into usage during the 1970s and by the end of the decade standard form factors had been established for drives using nominally 8-inch media (e.g., Shugart SA1000) and nominally 5.25-inch media (e.g., Seagate ST-506).
During the 1970s, captive production, dominated by IBM's production for its own use, remained the largest revenue channel for HDDs, though the relative importance of the OEM channel grew. Led by Control Data, Diablo Systems, CalComp and Memorex, the OEM segment reached $631 million in 1979, but still well below the $2.8 billion associated with captive production.[14]
1980s, the transition to the PC era
The 1980s saw the minicomputer age plateau as PCs were introduced. Manufacturers such as DEC and Hewlett-Packard continued to manufacture minicomputer compatible hard drive systems as industry demanded higher storage. Hewlett-Packard introduced the HP 7935 as one such drive. But it was clear that smaller Winchester storage systems were eclipsing large platter hard drives.

Hard disk drives for personal computers (PCs) were initially a rare and very expensive optional feature; systems typically had only the less expensive floppy disk drives or even cassette tape drives as both secondary storage and transport media. However by the late '80s, hard disk drives were standard on all but the cheapest PC and floppy disks were used almost solely as transport media.
Most hard disk drives in the early 1980s were sold to PC end users by systems integrators such as the Corvus Disk System or the systems manufacturer such as the Apple ProFile. The IBM PC XT in 1983, included an internal standard 10MB hard disk drive, and soon thereafter internal hard disk drives proliferated on personal computers.
HDDs continued to get smaller with the introduction of the 3.5-inch form factor in the middle of the decade Rodime 1983 and the 2.5-inch form factor PrairieTek 1988.
Industry participation peaked with about 75 active manufacturers in 1985 and then declined thereafter even though volume continued to climb: by 1989 reaching 22 million units and $23 billion in revenue.[15]
1990s
Even though there were a number of new entrants, industry participants continued to decline in total to 15 in 1999. Unit volume and industry revenue monotonically increased during the 1990s to 174 million units and $26 billion.[16]
The industry production consolidated around the 3.5-inch and 2.5 inch form factors; the larger form factors dying off while several smaller form factors were offered but achieved limited success, e.g. HP 1.3-inch Kittyhawk, IBM 1-inch Microdrive, etc..
2000 to present
In 2001 the HDD industry experienced its first ever decline in units and revenue.
The number of industry participants decreased to 6 in 2009 and 3 in 2013.
Unit production peaked in 2010 at about 650 million units and has been in a slow decline since then.[17]  Shipments in 2017 estimated at about 404 million units.[18]
Timeline
1956 – IBM 350A, shipment of prototype disk drive to Zellerbach, SF CA, USA
1957 – IBM 350, first production disk drive, 5 million characters (6-bit), equivalent to 3.75 megabytes.
1961 – IBM 1301 Disk Storage Unit introduced with one head per surface and aerodynamic flying heads, 28 million characters (6-bit) per module.
1961 – Bryant 4000 (Bryant Computer Products division of Ex-Cell-O) up to 205 MB on up to 26 29-inch diameter platters.[19]
1962 – IBM 1311 introduced removable disk packs containing 6 disks, storing 2 million characters per pack
1964 – IBM 2311 with 7.25 megabytes per disk pack
1964 – IBM 2310 removable cartridge disk drive with 1.02MB on one disk
1965 – IBM 2314 with 11 disks and 29MB per disk pack
1968 – Memorex is first to ship an IBM-plug-compatible disk drive
1970 – IBM 3330 Merlin, introduced error correction, 100MB per disk pack
1973 – IBM 3340 Winchester introduced removable sealed disk packs that included head and arm assembly, 35 or 70MB per pack
1973 – CDC SMD announced and shipped, 40MB disk pack
1976 – 1976 IBM 3350 "Madrid" – 317.5 megabytes, eight 14-inch disks, re-introduction of disk drive with fixed disk media
1979 – IBM 3370 introduced thin film heads, 571MB, non-removable
1979 – 1979 IBM 62PC "Piccolo" – 64.5 megabytes, six 8-inch disks, first 8-inch HDD
1980 – The IBM 3380 was the world's first gigabyte-capacity disk drive. Two 1.26 GB, head disk assemblies (essentially two HDDs) were packaged in a cabinet the size of a refrigerator,[20] weighed 455 kg (1000 lb), and had a price tag of US$81,000 (Model B4) which is US$246,304 in present-day terms.[21]
1980 – ST-506 first 5​1⁄4inch drive released with capacity of 5 megabytes, cost US$1500
1982 – HP 7935 404 megabyte, 7 platter hard drive for minicomputers, HP-IB bus, $27,000
1983 – RO351/RO352 first 3​1⁄2inch drive released with capacity of 10 megabytes[22]
1986 – Standardization of SCSI
1988 – PrairieTek 220 – 20 megabytes, two 2.5-inch disks, first 2.5 inch HDD
1989 – Jimmy Zhu and H. Neal Bertram from UCSD proposed exchange decoupled granular microstructure for thin film disk storage media, still used today.
1990 – 1990 IBM 0681 "Redwing" – 857 megabytes, twelve 5.25-inch disks. First HDD with PRML Technology (Digital Read Channel with 'partial response maximum likelihood' algorithm).
1991 – IBM 0663 "Corsair" – 1,004 megabytes, eight 3.5-inch disks; first HDD using magnetoresistive heads
1991 – Integral Peripherals 1820 "Mustang" – 21.4 megabytes, one 1.8-inch disk, first 1.8-inch HDD[23]
1992 – HP Kittyhawk  – 20MB, first 1.3-inch hard-disk drive
1993 – IBM 3390 model 9, the last Single Large Expensive Disk drive announced by IBM
1994 – IBM introduces Laser Textured Landing Zones (LZT)
1997 – IBM Deskstar 16GP "Titan" – 16,800 megabytes, five 3.5-inch disks; first (Giant Magnetoresistance) heads
1997 – Seagate introduces the first hard drive with fluid bearings[24]
1998 – UltraDMA/33 and ATAPI standardized
1999 – IBM releases the Microdrive in 170MB and 340MB capacities
2002 – (Parallel) ATA breaks 137 GB (128 GiB) addressing space barrier
2003 – Serial ATA introduced
2003 – IBM sells disk drive division to Hitachi
2004 – MK2001MTN first 0.85-inch drive released by Toshiba with capacity of 2 gigabytes[23]
2005 – Serial ATA 3Gbit/s standardized
2005 – Seagate introduces Tunnel MagnetoResistive Read Sensor (TMR) and Thermal Spacing Control
2005 – Introduction of faster SAS (Serial Attached SCSI)
2005 – First perpendicular magnetic recording (PMR) HDD shipped: Toshiba 1.8-inch 40/80GB[25]
2006 – First 200 GB 2.5" hard drive utilizing perpendicular recording (Toshiba)
2006 – Fujitsu develops heat-assisted magnetic recording (HAMR) that could one day achieve up to 50 terabits per square inch densities[26]
2010 – First hard drive manufactured by using the Advanced Format of 4,096 bytes a block ("4K") instead of 512 bytes a block[27]
2011 – Floods hit many hard drive factories. Predictions of a worldwide shortage of hard disk drives cause prices to double.[28][29][30]
2012 – Western Digital announces the first 2.5-inch, 5mm thick drive, and the first 2.5-inch, 7mm thick drive with two platters[31] (Western Digital)
2012 – TDK demonstrates 2TB on a single 3.5-inch platter[32]
2012 – WDC acquires HGST operating it as a wholly owned subsidiary. WDC then provides rights to Toshiba.[33] allowing it to re-enter the 3.5" desktop hard disk drive market.[34]
2013 – HGST ships first modern[35] helium-filled hard disk drive; He6 with 6TB on 7 platters[36] (announced in 2012).[37]
2013 – Seagate claims first to ship shingled magnetic recording (SMR) HDDs[38]
2018 – Seagate claims data transfer speeds of 480MB/s out of a conventional hard drive rotating at 7200 RPM using two independent actuator arms each holding eight read-write heads (two per platter) and announces plans for launch in 2019 under the mach.2 trademark. This is similar to the read speeds of low-end SSDs (write speed on an SSD is lower than the read speed)[39]
Manufacturing history


Manufacturing began in California's Silicon Valley in 1957 with IBM's production shipment of the first HDD, the IBM RAMAC 350.  The industry grew slowly at first with three additional companies in the market by 1964, Anelex Corp., Bryant Computer Products and Data Products Corp..[40]  The industry grew rapidly in the late 1960s and again in the 1980s reaching a peak of 75 manufacturers in 1984.[41] There have been at least 221 companies manufacturing hard disk drives[42][43][44][45] but most of that industry has vanished through bankruptcy or mergers and acquisitions. Surviving manufacturers are Seagate, Toshiba and Western Digital (WD) with Toshiba as the senior participant having entered the market in 1977,[46] twenty years after IBM started the market.
From beginning and into the early 1980s manufacturing was mainly by US firms in the United States at locations such as Silicon Valley, Los Angeles, Minnesota and Oklahoma City.[43]:Table 7  In the 1980s US firms, beginning with Seagate, began to shift production to Singapore and then other locations in southeast Asia.  In a span of seven years, 1983 to 1990, Singapore became the single largest location of HDD production, amounting to 55% of worldwide production.[43]:Table 9  Japanese HDD companies later also moved their production to southeast Asia.[43]:Table 10  Today the three remaining firms all produce their units in the Pacific Rim.
By the 1990s the dollar value of magnetic recording devices produced by companies located in California's "Silicon Valley" exceeded the dollar value of semiconductor devices produced there leading some to suggest that a more appropriate name for this area would be "Iron Oxide Valley," after the magnetic material coating the disks.[47]  All three remaining firms still have significant activities in Silicon Valley, but no HDD manufacturing. Western Digital still manufactures its read-write head wafers in Fremont CA.
See also
History of floppy disks
History of IBM magnetic disk drives