95-535: (Redirected from HDDs ) HDD may refer to: H. D. Deve Gowda , former Prime Minister of India Hard disk drive Hand Drawn Dracula , a record label Head-down display Heating degree day High definition display Honorary Doctor of Divinity Horizontal Directional Drilling Hyderabad Airport (Sindh) (IATA:HDD), in Pakistan /dev/hdd ; see Device file § naming conventions Hard Drive Divinity,
190-684: A spindle that holds flat circular disks, called platters , which hold the recorded data. The platters are made from a non-magnetic material, usually aluminum alloy , glass , or ceramic . They are coated with a shallow layer of magnetic material typically 10–20 nm in depth, with an outer layer of carbon for protection. For reference, a standard piece of copy paper is 0.07–0.18 mm (70,000–180,000 nm) thick. The platters in contemporary HDDs are spun at speeds varying from 4200 rpm in energy-efficient portable devices, to 15,000 rpm for high-performance servers. The first HDDs spun at 1,200 rpm and, for many years, 3,600 rpm
285-522: A stepper motor . Early hard disk drives wrote data at some constant bits per second, resulting in all tracks having the same amount of data per track, but modern drives (since the 1990s) use zone bit recording , increasing the write speed from inner to outer zone and thereby storing more data per track in the outer zones. In modern drives, the small size of the magnetic regions creates the danger that their magnetic state might be lost because of thermal effects — thermally induced magnetic instability which
380-416: A "stopgap" technology between PMR and Seagate's intended successor heat-assisted magnetic recording (HAMR). SMR utilises overlapping tracks for increased data density, at the cost of design complexity and lower data access speeds (particularly write speeds and random access 4k speeds). By contrast, HGST (now part of Western Digital ) focused on developing ways to seal helium -filled drives instead of
475-455: A 3.5-inch (89 mm) mounting frame with a built-in heat sink. Western Digital said that the new drives are 35 percent faster than the previous generation. On September 12, 2008, Western Digital shipped a 500 GB 2.5-inch (64 mm) notebook hard drive which is part of their Scorpio Blue series of notebook hard drives. On January 27, 2009, Western Digital shipped the first 2 TB internal hard disk drive. On March 30, 2009, they entered
570-569: A Field Generation Layer (FGL) and a Spin Injection Layer (SIL), and the FGL produces a magnetic field using spin-polarised electrons originating in the SIL, which is a form of spin torque energy. A typical HDD has two electric motors: a spindle motor that spins the disks and an actuator (motor) that positions the read/write head assembly across the spinning disks. The disk motor has an external rotor attached to
665-418: A bit cell comprising about 18 magnetic grains (11 by 1.6 grains). Since the mid-2000s, areal density progress has been challenged by a superparamagnetic trilemma involving grain size, grain magnetic strength and ability of the head to write. In order to maintain acceptable signal-to-noise, smaller grains are required; smaller grains may self-reverse ( electrothermal instability ) unless their magnetic strength
760-489: A breather port, unlike their air-filled counterparts. Other recording technologies are either under research or have been commercially implemented to increase areal density, including Seagate's heat-assisted magnetic recording (HAMR). HAMR requires a different architecture with redesigned media and read/write heads, new lasers, and new near-field optical transducers. HAMR is expected to ship commercially in late 2024, after technical issues delayed its introduction by more than
855-446: A component of the IBM 305 RAMAC system. It was approximately the size of two large refrigerators and stored five million six-bit characters (3.75 megabytes ) on a stack of 52 disks (100 surfaces used). The 350 had a single arm with two read/write heads, one facing up and the other down, that moved both horizontally between a pair of adjacent platters and vertically from one pair of platters to
950-1080: A decade, from earlier projections as early as 2009. HAMR's planned successor, bit-patterned recording (BPR), has been removed from the roadmaps of Western Digital and Seagate. Western Digital's microwave-assisted magnetic recording (MAMR), also referred to as energy-assisted magnetic recording (EAMR), was sampled in 2020, with the first EAMR drive, the Ultrastar HC550, shipping in late 2020. Two-dimensional magnetic recording (TDMR) and "current perpendicular to plane" giant magnetoresistance (CPP/GMR) heads have appeared in research papers. Some drives have adopted dual independent actuator arms to increase read/write speeds and compete with SSDs. A 3D-actuated vacuum drive (3DHD) concept and 3D magnetic recording have been proposed. Depending upon assumptions on feasibility and timing of these technologies, Seagate forecasts that areal density will grow 20% per year during 2020–2034. The highest-capacity HDDs shipping commercially in 2024 are 32 TB. The capacity of
1045-401: A hard disk drive, as reported by an operating system to the end user, is smaller than the amount stated by the manufacturer for several reasons, e.g. the operating system using some space, use of some space for data redundancy, space use for file system structures. Confusion of decimal prefixes and binary prefixes can also lead to errors. Western Digital Western Digital Corporation
SECTION 10
#17328511138141140-422: A moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage , retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box . Hard disk drives were introduced by IBM in 1956, and were
1235-446: A number of hardware companies. These included graphics cards (through its Paradise Systems subsidiary, purchased 1986, which later became Western Digital Imaging), core logic chipsets (by purchasing Faraday Electronics Inc. in 1987), SCSI controller chips for disk and tape devices (by purchasing ADSI in 1986), networking ( WD8003 , WD8013 Ethernet and WD8003S StarLAN ). They did well (especially Paradise, which produced one of
1330-469: A removable disk module, which included both the disk pack and the head assembly, leaving the actuator motor in the drive upon removal. Later "Winchester" drives abandoned the removable media concept and returned to non-removable platters. In 1974, IBM introduced the swinging arm actuator, made feasible because the Winchester recording heads function well when skewed to the recorded tracks. The simple design of
1425-456: A result, there may be 100 or more load cycles per hour, and the 300,000 load cycles rating of a WD GP drive may be exceeded in less than a year. On April 21, 2008, Western Digital announced the next generation of its 10,000 rpm SATA WD Raptor series of hard drives. The new drives, called WD VelociRaptor , featured 300 GB capacity and 2.5-inch (64 mm) platters enclosed in the IcePack,
1520-530: A second set. Variants of the IBM 350 were the IBM 355 , IBM 7300 and IBM 1405 . In 1961, IBM announced, and in 1962 shipped, the IBM ;1301 disk storage unit, which superseded the IBM 350 and similar drives. The 1301 consisted of one (for Model 1) or two (for model 2) modules, each containing 25 platters, each platter about 1 ⁄ 8 -inch (3.2 mm) thick and 24 inches (610 mm) in diameter. While
1615-481: A single 1 TB hard drive, the largest in its My Book line. In 2007, Western Digital acquired magnetic media maker Komag. Also in the same year, Western Digital adopted perpendicular recording technology in its line of notebook and desktop drives. This allowed it to produce notebook and desktop drives in the largest classes of the time. Western Digital also started to produce the energy efficient GP (Green Power) range of drives. In 2007, Western Digital announced
1710-576: A slump. In 1994, Western Digital began producing hard drives at its Malaysian factory, employing 13,000 people. Products and ideas of this time did not go far. The Portfolio drive (a 3-inch (76 mm) form factor model, developed with JT Storage ) was a flop, as was the SDX hard disk to CD-ROM interface. Western Digital's drives started to slip further behind competing products, and quality began to suffer; system builders and PC enthusiasts who used to recommend Western Digital above all else, were going to
1805-616: A swing arm drive, the IBM 0680 (Piccolo), with eight inch platters, exploring the possibility that smaller platters might offer advantages. Other eight inch drives followed, then 5 + 1 ⁄ 4 in (130 mm) drives, sized to replace the contemporary floppy disk drives . The latter were primarily intended for the then fledgling personal computer (PC) market. Over time, as recording densities were greatly increased, further reductions in disk diameter to 3.5" and 2.5" were found to be optimum. Powerful rare earth magnet materials became affordable during this period, and were complementary to
1900-423: A thin film of ferromagnetic material on both sides of a disk. Sequential changes in the direction of magnetization represent binary data bits . The data is read from the disk by detecting the transitions in magnetization. User data is encoded using an encoding scheme, such as run-length limited encoding, which determines how the data is represented by the magnetic transitions. A typical HDD design consists of
1995-499: A tiny fraction of the detected errors end up as not correctable. Examples of specified uncorrected bit read error rates include: Within a given manufacturers model the uncorrected bit error rate is typically the same regardless of capacity of the drive. The worst type of errors are silent data corruptions which are errors undetected by the disk firmware or the host operating system; some of these errors may be caused by hard disk drive malfunctions while others originate elsewhere in
SECTION 20
#17328511138142090-763: Is an American data storage company headquartered in San Jose, California . It has a decades-long history in the electronics industry as an integrated circuit and data memory technology developer. It is one of the world's largest computer hard disk drive (HDD) manufacturers, along with producing solid-state drives (SSDs) and flash memory devices. The company produces its data storage products for everyday users, gamers, creative professionals and small businesses up to enterprises and public clouds. Its portfolio of digital storage includes internal and external drives for desktop, mobile, photography, gaming, security, data centers and artificial intelligence (AI) . Its competitors include
2185-446: Is capable of scheduling reads and writes efficiently on the platter surfaces and remapping sectors of the media that have failed. Modern drives make extensive use of error correction codes (ECCs), particularly Reed–Solomon error correction . These techniques store extra bits, determined by mathematical formulas, for each block of data; the extra bits allow many errors to be corrected invisibly. The extra bits themselves take up space on
2280-586: Is commonly known as the " superparamagnetic limit ". To counter this, the platters are coated with two parallel magnetic layers, separated by a three-atom layer of the non-magnetic element ruthenium , and the two layers are magnetized in opposite orientation, thus reinforcing each other. Another technology used to overcome thermal effects to allow greater recording densities is perpendicular recording (PMR), first shipped in 2005, and as of 2007 , used in certain HDDs. Perpendicular recording may be accompanied by changes in
2375-461: Is different from Wikidata All article disambiguation pages All disambiguation pages Hard disk drive A hard disk drive ( HDD ), hard disk , hard drive , or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads , usually arranged on
2470-669: Is improving faster than HDDs. NAND has a higher price elasticity of demand than HDDs, and this drives market growth. During the late 2000s and 2010s, the product life cycle of HDDs entered a mature phase, and slowing sales may indicate the onset of the declining phase. The 2011 Thailand floods damaged the manufacturing plants and impacted hard disk drive cost adversely between 2011 and 2013. In 2019, Western Digital closed its last Malaysian HDD factory due to decreasing demand, to focus on SSD production. All three remaining HDD manufacturers have had decreasing demand for their HDDs since 2014. A modern HDD records data by magnetizing
2565-418: Is increased, but known write head materials are unable to generate a strong enough magnetic field sufficient to write the medium in the increasingly smaller space taken by grains. Magnetic storage technologies are being developed to address this trilemma, and compete with flash memory –based solid-state drives (SSDs). In 2013, Seagate introduced shingled magnetic recording (SMR), intended as something of
2660-460: Is shaped rather like an arrowhead and is made of doubly coated copper magnet wire . The inner layer is insulation, and the outer is thermoplastic, which bonds the coil together after it is wound on a form, making it self-supporting. The portions of the coil along the two sides of the arrowhead (which point to the center of the actuator bearing) then interact with the magnetic field of the fixed magnet. Current flowing radially outward along one side of
2755-588: Is specified in unit prefixes corresponding to powers of 1000: a 1- terabyte (TB) drive has a capacity of 1,000 gigabytes , where 1 gigabyte = 1 000 megabytes = 1 000 000 kilobytes (1 million) = 1 000 000 000 bytes (1 billion). Typically, some of an HDD's capacity is unavailable to the user because it is used by the file system and the computer operating system , and possibly inbuilt redundancy for error correction and recovery. There can be confusion regarding storage capacity, since capacities are stated in decimal gigabytes (powers of 1000) by HDD manufacturers, whereas
2850-604: Is the WD1600ADFD, with 160 GB of disk space. As of 2004 , the Western Digital Raptor drives have a five-year warranty, making them a more attractive choice for inexpensive storage servers , where a large number of drives in constant use increases the likelihood of a drive failure. In 2006, Western Digital introduced its My Book line of mass market external hard drives that feature a compact book-like design. On October 7, 2007, Western Digital released several editions of
2945-633: The Apple Macintosh . Many Macintosh computers made between 1986 and 1998 featured a SCSI port on the back, making external expansion simple. Older compact Macintosh computers did not have user-accessible hard drive bays (indeed, the Macintosh 128K , Macintosh 512K , and Macintosh Plus did not feature a hard drive bay at all), so on those models, external SCSI disks were the only reasonable option for expanding upon any internal storage. HDD improvements have been driven by increasing areal density , listed in
HDD - Misplaced Pages Continue
3040-694: The JB code (the 2 MB models had the BB code). The first 8 MB cache drive was the 100 GB WD1000JB, followed by other models starting with 40 GB capacity. Western Digital advertised the JB models for cost-effective file servers . In October 2001, Western Digital restated its prior year results to reflect the adoption of SEC Staff Accounting Bulletin No.101 and the reclassification of Connex and SANavigator results as discontinued operations. In 2003, Western Digital acquired most of
3135-564: The Shannon limit and thus provide the highest storage density available. Typical hard disk drives attempt to "remap" the data in a physical sector that is failing to a spare physical sector provided by the drive's "spare sector pool" (also called "reserve pool"), while relying on the ECC to recover stored data while the number of errors in a bad sector is still low enough. The S.M.A.R.T ( Self-Monitoring, Analysis and Reporting Technology ) feature counts
3230-511: The WD1402A UART . During the early 1970s, the company focused on making and selling calculator chips, and by 1975, Western Digital was the largest independent calculator chip maker in the world. The oil crisis of the mid-1970s and the bankruptcy of its biggest calculator customer, Bowmar Instrument, changed its fortunes, however, and in 1976 Western Digital declared Chapter 11 bankruptcy. After this, Emerson Electric withdrew their support of
3325-600: The WD16 , and their own Pascal MicroEngine microcomputer which ran the UCSD p-System Version III and UCSD Pascal . However, the WD integrated circuit that arguably drove Western's forward integration was the FD1771 , one of the first single-chip floppy disk drive formatter/controllers, which could replace significant amounts of TTL logic. The FD1771 and its kin were Western Digital's first entry into
3420-535: The WD42C22 "Vanilla" , the first single-chip ATA hard disk controller. 1988 also brought what would be the biggest change in Western Digital's history. That year, Western Digital bought the hard drive production assets of PC hardware maker Tandon ; the first products of that union under Western Digital's own name were the "Centaur" series of ATA and XT attachment drives. By 1991, things were starting to slow down, as
3515-503: The solid-state drive market with the acquisition of Siliconsystems, Inc. Its acquisition was unsuccessful, and few years later Western Digital discontinued all solid-state storage products based on Siliconsystems design ( SiliconEdge and SiliconDrive families of SSDs and memory cards), but its inventions was used later in development of various other solid-state storage products, with larger developments going on after 2016 acquisition of SanDisk. On July 27, 2009, Western Digital announced
3610-494: The 1980s, the family of controllers based on the WD1003 provided the bulk of Western Digital's revenues and profits, and for a time generated enormous corporate growth. Much of the mid-to-late 1980s saw an effort by Western Digital to use the profits from their ATA storage controllers to become a general-purpose OEM hardware supplier for the PC industry. As a result, Western Digital purchased
3705-520: The HDD, but allow higher recording densities to be employed without causing uncorrectable errors, resulting in much larger storage capacity. For example, a typical 1 TB hard disk with 512-byte sectors provides additional capacity of about 93 GB for the ECC data. In the newest drives, as of 2009 , low-density parity-check codes (LDPC) were supplanting Reed–Solomon; LDPC codes enable performance close to
3800-477: The IBM GV (Gulliver) drive, invented at IBM's UK Hursley Labs, became IBM's most licensed electro-mechanical invention of all time, the actuator and filtration system being adopted in the 1980s eventually for all HDDs, and still universal nearly 40 years and 10 billion arms later. Like the first removable pack drive, the first "Winchester" drives used platters 14 inches (360 mm) in diameter. In 1978, IBM introduced
3895-465: The PC industry moved from ST-506 and ESDI drives to ATA and SCSI, and thus were buying fewer hard disk controller boards. That year saw the rise of Western Digital's Caviar drives, brand new designs that used the latest in embedded servo and computerized diagnostic systems. Eventually, the successful sales of the Caviar drives resulted in Western Digital starting to sell some of its divisions. Paradise
HDD - Misplaced Pages Continue
3990-459: The SN850 became available. The only higher-performing SSD at that time was Intel's Optane line, which is a non-consumer, workstation/server-based SSD with a cost of over five times the SN850. In June 2021, users reported that their My Book Live NAS drives, which were discontinued products last manufactured in 2013, had been erased, leading to the company advising that the devices be disconnected from
4085-507: The WD GP drive touting rotational speed "between 7200 and 5400 rpm", which is technically correct while also being misleading; the drive spins at 5405 rpm, and the Green Power spin speed is not variable. WD GP drives are programmed to unload the heads whenever idle for a very short period of time. Many Linux installations write to the file system a few times a minute in the background. As
4180-443: The arrowhead and radially inward on the other produces the tangential force . If the magnetic field were uniform, each side would generate opposing forces that would cancel each other out. Therefore, the surface of the magnet is half north pole and half south pole, with the radial dividing line in the middle, causing the two sides of the coil to see opposite magnetic fields and produce forces that add instead of canceling. Currents along
4275-499: The assets of bankrupt one-time market leading magnetic hard drive read-write head developer Read-Rite Corporation for $ 95 million. In the same year, Western Digital offered the first 10,000 rpm Serial ATA HDD, the WD360GD " Raptor ", with a capacity of 36 GB and an average access time of less than six milliseconds. Soon, the 74 GB WD740GD followed, which was also much quieter. In 2004, Western Digital redesigned its logo for
4370-658: The best VGA cards of the era), but storage-related chips and disk controllers were their biggest money makers. In 1986, they introduced the WD33C93 single-chip SCSI interface, which was used in the first 16-bit bus mastering SCSI host adapter, the WD7000 "FASST" ; in 1987 they introduced the WD37C65 , a single-chip implementation of the PC/AT's floppy disk controller circuitry, and the grandfather of modern super I/O chips; in 1988 they introduced
4465-447: The case of embedded servo, otherwise known as sector servo technology). The servo feedback optimizes the signal-to-noise ratio of the GMR sensors by adjusting the voice coil motor to rotate the arm. A more modern servo system also employs milli and/or micro actuators to more accurately position the read/write heads. The spinning of the disks uses fluid-bearing spindle motors. Modern disk firmware
4560-552: The company autonomously from WD, the Chinese Ministry of Commerce issued a decision allowing the company to begin integrating HGST into its main business, but under the condition that it maintain the HGST brand and sales team for at least two more years. The HGST brand was phased out in 2018, and since then, all HGST-branded products are just branded Western Digital. In May 2016, Western Digital acquired SanDisk for US$ 19 billion. In
4655-511: The company towards flash drive production, leaving the company with just two HDD production facilities in Thailand. The company ranked 158th on the 2018 Fortune 500 of the largest United States corporations by revenue. In June 2019, Kioxia experienced a power cut at one of its factories in Yokkaichi, Japan, resulting in the loss of at least 6 exabytes of flash memory, with some sources estimating
4750-538: The company. Chuck Missler joined Western Digital as chairman and chief executive in June 1977, and became the largest shareholder of Western Digital. In 1973, Western Digital established its Malaysian plant, initially to manufacture semiconductors. Western Digital introduced several products during the late 1970s, including the MCP-1600 multi-chip, microcoded CPU . The MCP-1600 was used to implement DEC 's LSI-11 system,
4845-531: The competition, particularly Maxtor , whose products had improved significantly by the late 1990s. In an attempt to turn the tide in 1998, Western Digital recruited the help of IBM . This agreement gave Western Digital the rights to use certain IBM technologies, including giant magneto-resistive (GMR) heads and access to IBM production facilities. The result was the Expert line of drives, introduced in early 1999. The idea worked, and Western Digital regained respect in
SECTION 50
#17328511138144940-441: The connection between the drive and the host. The rate of areal density advancement was similar to Moore's law (doubling every two years) through 2010: 60% per year during 1988–1996, 100% during 1996–2003 and 30% during 2003–2010. Speaking in 1997, Gordon Moore called the increase "flabbergasting", while observing later that growth cannot continue forever. Price improvement decelerated to −12% per year during 2010–2017, as
5035-462: The contamination. WD experienced a cyberattack breaching the company's systems on March 23, 2023. On April 2, the company proactively took some services offline, including My Cloud , to examine the extent of the intrusion. The hackers allegedly stole around 10 TB of data from the company, including customer information, and demanded a ransom of "minimum 8 figures" to not publish the stolen data. Merger talks with Kioxia resumed in 2023, but
5130-484: The data management and storage companies Seagate Technology and Micron Technology. Western Digital develops and delivers its HDDs, SSDs, memory cards, NVMe, NAS, RAID and other memory technology solutions under its Western Digital, SanDisk , SanDisk Professional , WD and WD_BLACK brands. The company holds approximately 13,000 active patents and maintains a global presence with 12+ manufacturing facilities and other operations in more than 30 countries. Western Digital
5225-564: The data storage industry; by the early 1980s, they were making hard disk drive controllers, and in 1983, they won the contract to provide IBM with controllers for the PC/AT . That controller, the WD1003 , became the basis of the ATA interface (which Western Digital developed along with Compaq and Control Data Corporation's MPI division, now owned by Seagate Technology ), starting in 1986. Throughout most of
5320-407: The desktop and consumer electronics markets to Toshiba , in exchange for one of its 2.5-inch hard drive factories in Thailand. In December 2013, Western Digital stopped manufacturing parallel ATA hard disk drives for laptops (2.5-inch form factor) and desktop PCs (3.5-inch form factor). Until that time, they were last hard disk manufacturer to produce PATA hard disk drives. Furthermore, they were
5415-449: The disks; the stator windings are fixed in place. Opposite the actuator at the end of the head support arm is the read-write head; thin printed-circuit cables connect the read-write heads to amplifier electronics mounted at the pivot of the actuator. The head support arm is very light, but also stiff; in modern drives, acceleration at the head reaches 550 g . The actuator is a permanent magnet and moving coil motor that swings
5510-522: The dominant secondary storage device for general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern era of servers and personal computers , though personal computing devices produced in large volume, like mobile phones and tablets , rely on flash memory storage devices. More than 224 companies have produced HDDs historically , though after extensive industry consolidation, most units are manufactured by Seagate , Toshiba , and Western Digital . HDDs dominate
5605-467: The earlier IBM disk drives used only two read/write heads per arm, the 1301 used an array of 48 heads (comb), each array moving horizontally as a single unit, one head per surface used. Cylinder-mode read/write operations were supported, and the heads flew about 250 micro-inches (about 6 μm) above the platter surface. Motion of the head array depended upon a binary adder system of hydraulic actuators which assured repeatable positioning. The 1301 cabinet
5700-458: The first 1 TB mobile hard disk drive, which shipped as both a Passport series portable USB drive as well as a Scorpio Blue series notebook drive. In October 2009, Western Digital announced the shipment of first 3 TB internal hard disk drive, which has 750 GB-per-platter density with SATA interface. In March 2011, Western Digital agreed to acquire parts of the storage unit of Hitachi , HGST , for about $ 4.3 billion of which $ 3.5 billion
5795-459: The first time since 1997, with the design of new logo focusing on the company's initials ("WD"). In 2005, Western Digital released a 150 GB version, the WD1500ADFD, which was also available in a special version with a transparent window enabling the user to see the drive's heads move over the platters while the drive read and wrote data (Raptor X, WD1500AHFD). The biggest capacity 3,5 inch Raptor
SECTION 60
#17328511138145890-443: The growth of areal density slowed. The rate of advancement for areal density slowed to 10% per year during 2010–2016, and there was difficulty in migrating from perpendicular recording to newer technologies. As bit cell size decreases, more data can be put onto a single drive platter. In 2013, a production desktop 3 TB HDD (with four platters) would have had an areal density of about 500 Gbit/in which would have amounted to
5985-416: The heads to the desired position. A metal plate supports a squat neodymium–iron–boron (NIB) high-flux magnet . Beneath this plate is the moving coil, often referred to as the voice coil by analogy to the coil in loudspeakers , which is attached to the actuator hub, and beneath that is a second NIB magnet, mounted on the bottom plate of the motor (some drives have only one magnet). The voice coil itself
6080-680: The internet. In August 2021, Western Digital and Japanese memory-chip supplier Kioxia (formerly Toshiba Memory) began working out the details of a merger to be finalized in September 2021. In October of the same year, it became clear that the merger talks stalled. In February 2022, Western Digital and Kioxia reported that contamination issues have affected the output of their flash memory joint-production factories, with WD admitting that at least 6.5 exabytes of memory output being affected. The Kiakami and Yokkaichi factories in Japan stopped producing due to
6175-427: The largest hard drive had a capacity of 15 TB, while the largest capacity SSD had a capacity of 100 TB. As of 2018 , HDDs were forecast to reach 100 TB capacities around 2025, but as of 2019 , the expected pace of improvement was pared back to 50 TB by 2026. Smaller form factors, 1.8-inches and below, were discontinued around 2010. The cost of solid-state storage (NAND), represented by Moore's law ,
6270-533: The loss as high as 15 exabytes. Western Digital used (and still uses) Kioxia's facilities for making its own flash memory chips. In November 2020, Western Digital produced a new consumer SSD, the WD Black SN850 1TB. Using a proprietary NVMe version 1.4 controller ("G2"), it is reported to outperform Samsung's 980 Pro 1TB as well as other, new-to-market SSDs containing the Phison E18 controller that arrived after
6365-444: The magnetization of the material passing immediately under it. In modern drives, there is one head for each magnetic platter surface on the spindle, mounted on a common arm. An actuator arm (or access arm) moves the heads on an arc (roughly radially) across the platters as they spin, allowing each head to access almost the entire surface of the platter as it spins. The arm is moved using a voice coil actuator or, in some older designs,
6460-422: The manufacturing of the read/write heads to increase the strength of the magnetic field created by the heads. In 2004, a higher-density recording media was introduced, consisting of coupled soft and hard magnetic layers. So-called exchange spring media magnetic storage technology, also known as exchange coupled composite media , allows good writability due to the write-assist nature of the soft layer. However,
6555-420: The most commonly used operating systems report capacities in powers of 1024, which results in a smaller number than advertised. Performance is specified as the time required to move the heads to a track or cylinder (average access time), the time it takes for the desired sector to move under the head (average latency , which is a function of the physical rotational speed in revolutions per minute ), and finally,
6650-559: The norm in most computer installations and reached capacities of 300 megabytes by the early 1980s. Non-removable HDDs were called "fixed disk" drives. In 1963, IBM introduced the 1302, with twice the track capacity and twice as many tracks per cylinder as the 1301. The 1302 had one (for Model 1) or two (for Model 2) modules, each containing a separate comb for the first 250 tracks and the last 250 tracks. Some high-performance HDDs were manufactured with one head per track, e.g. , Burroughs B-475 in 1964, IBM 2305 in 1970, so that no time
6745-451: The only manufacturer that had 250 GB and 320 GB in 2.5-inch form factor. In February 2014, Western Digital announced a new "Purple" line of hard disk drives for use in video surveillance systems, with capacities from 1 to 4 TB. They feature internal optimizations for applications that involve near-constant disk writing, and "AllFrame" technology which is designed to reduce write errors. In October 2015, after being required to operate
6840-530: The platters, increasing areal density. Normally hard drive recording heads have a pole called a main pole that is used for writing to the platters, and adjacent to this pole is an air gap and a shield. The write coil of the head surrounds the pole. The STO device is placed in the air gap between the pole and the shield to increase the strength of the magnetic field created by the pole; FC-MAMR technically doesn't use microwaves, but uses technology employed in MAMR. The STO has
6935-441: The press and among users, even despite a recall in 2000 (which was due to bad motor driver chips). Western Digital later broke ties with IBM. In 2001, Western Digital became the first manufacturer to offer mainstream ATA hard disk drives with 8 MiB of disk buffer . At that time, most desktop hard disk drives had 2 MB of buffer. Western Digital labeled these 8 MB models as "Special Edition" and distinguished them with
7030-416: The revenue of hard disk drives as of 2017 . Though SSDs have four to nine times higher cost per bit, they are replacing HDDs in applications where speed, power consumption, small size, high capacity and durability are important. As of 2019 , the cost per bit of SSDs is falling, and the price premium over HDDs has narrowed. The primary characteristics of an HDD are its capacity and performance . Capacity
7125-759: The sale of the jointly owned NAND production facility in Japan. In June 2018, Western Digital acquired Wearable, Inc., a small company based in the Chicago area that produced the SanDisk Wireless Drive and SanDisk Connect Wireless Stick, which were derived from Wearable Inc.’s AirStash wireless server platform. In May 2018, Toshiba reached an agreement with the Bain consortium about the sale of that chip unit. In July 2018, Western Digital announced their plan to close their hard disk production facility in Kuala Lumpur to shift
7220-417: The service. In September 2017, Western Digital acquired Tegile Systems , maker of flash memory storage arrays . Western Digital rebranded Tegile as IntelliFlash and sold it to DataDirect Networks in September 2019. In October 2017, Western Digital shipped the world's first 14 TB HDD, the helium-filled HGST Ultrastar Hs14. In December 2017, Western Digital reached an agreement with Toshiba about
7315-427: The speed at which the data is transmitted (data rate). The two most common form factors for modern HDDs are 3.5-inch, for desktop computers, and 2.5-inch, primarily for laptops. HDDs are connected to systems by standard interface cables such as SATA (Serial ATA), USB , SAS ( Serial Attached SCSI ), or PATA (Parallel ATA) cables. The first production IBM hard disk drive, the 350 disk storage , shipped in 1957 as
7410-438: The stack of disk platters when the drive was powered down. Instead, the heads were allowed to "land" on a special area of the disk surface upon spin-down, "taking off" again when the disk was later powered on. This greatly reduced the cost of the head actuator mechanism, but precluded removing just the disks from the drive as was done with the disk packs of the day. Instead, the first models of "Winchester technology" drives featured
7505-508: The summer of 2017, Western Digital licensed the Fusion-io /SanDisk ION Accelerator software to One Stop Systems. In 2016, HGST closed its Malaysian plant. In April 2017, Western Digital moved its headquarters from Irvine, California to HGST's headquarters in San Jose, California. In August 2017, Western Digital bought cloud storage provider Upthere, with the intention to continue building out
7600-447: The swing arm actuator design to make possible the compact form factors of modern HDDs. As the 1980s began, HDDs were a rare and very expensive additional feature in PCs, but by the late 1980s, their cost had been reduced to the point where they were standard on all but the cheapest computers. Most HDDs in the early 1980s were sold to PC end users as an external, add-on subsystem. The subsystem
7695-439: The table above. Applications expanded through the 2000s, from the mainframe computers of the late 1950s to most mass storage applications including computers and consumer applications such as storage of entertainment content. In the 2000s and 2010s, NAND began supplanting HDDs in applications requiring portability or high performance. NAND performance is improving faster than HDDs, and applications for HDDs are eroding. In 2018,
7790-400: The thermal stability is determined only by the hardest layer and not influenced by the soft layer. Flux control MAMR (FC-MAMR) allows a hard drive to have increased recording capacity without the need for new hard disk drive platter materials. MAMR hard drives have a microwave generating spin torque generator (STO) on the read/write heads which allows physically smaller bits to be recorded to
7885-475: The top and bottom of the coil produce radial forces that do not rotate the head. The HDD's electronics controls the movement of the actuator and the rotation of the disk and transfers data to/from a disk controller . Feedback of the drive electronics is accomplished by means of special segments of the disk dedicated to servo feedback. These are either complete concentric circles (in the case of dedicated servo technology) or segments interspersed with real data (in
7980-491: The total number of errors in the entire HDD fixed by ECC (although not on all hard drives as the related S.M.A.R.T attributes "Hardware ECC Recovered" and "Soft ECC Correction" are not consistently supported), and the total number of performed sector remappings, as the occurrence of many such errors may predict an HDD failure . The "No-ID Format", developed by IBM in the mid-1990s, contains information about which sectors are bad and where remapped sectors have been located. Only
8075-628: The transformed state of CPUs in Hyperdimension Neptunia Handan East railway station , China Railway pinyin code HDD Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title HDD . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=HDD&oldid=1145132703 " Category : Disambiguation pages Hidden categories: Short description
8170-433: The usual filtered air. Since turbulence and friction are reduced, higher areal densities can be achieved due to using a smaller track width, and the energy dissipated due to friction is lower as well, resulting in a lower power draw. Furthermore, more platters can be fit into the same enclosure space, although helium gas is notoriously difficult to prevent escaping. Thus, helium drives are completely sealed and do not have
8265-499: The volume of storage produced ( exabytes per year) for servers. Though production is growing slowly (by exabytes shipped ), sales revenues and unit shipments are declining, because solid-state drives (SSDs) have higher data-transfer rates, higher areal storage density, somewhat better reliability, and much lower latency and access times. The revenues for SSDs, most of which use NAND flash memory , slightly exceeded those for HDDs in 2018. Flash storage products had more than twice
8360-520: Was about the size of three large refrigerators placed side by side, storing the equivalent of about 21 million eight-bit bytes per module. Access time was about a quarter of a second. Also in 1962, IBM introduced the model 1311 disk drive, which was about the size of a washing machine and stored two million characters on a removable disk pack . Users could buy additional packs and interchange them as needed, much like reels of magnetic tape . Later models of removable pack drives, from IBM and others, became
8455-938: Was called off after Kioxia's largest shareholder Bain Capital and indirect shareholder SK Hynix declared their opposition to the deal in October. In the October earnings call , Western Digital announced it would spin off its flash memory business, effectively reversing the SanDisk merger by the second half of 2024. On May 16, 2024, Western Digital announced the world's first 6 TB external hard disk drive in 2.5 inch form factor. Western Digital's offerings include HDDs and SSDs for computing devices (e.g. PCs, security surveillance systems, gaming consoles and set-top boxes ); NAND-flash embedded storage products for mobile devices, notebook PCs and other portable and IoT devices; and NAND flash memory wafers. Western Digital's embedded storage devices include
8550-721: Was founded on April 23, 1970, by Alvin B. Phillips, a Motorola employee, as General Digital Corporation , initially a manufacturer of MOS test equipment. It was originally based in Newport Beach, California , shortly thereafter moving to Santa Ana, California , and would go on to become one of the largest technology firms headquartered in Orange County . It rapidly became a specialty semiconductor maker, with start-up capital provided by several individual investors and industrial giant Emerson Electric . Around July 1971, it adopted its current name and soon introduced its first product,
8645-427: Was lost physically moving the heads to a track and the only latency was the time for the desired block of data to rotate into position under the head. Known as fixed-head or head-per-track disk drives, they were very expensive and are no longer in production. In 1973, IBM introduced a new type of HDD code-named " Winchester ". Its primary distinguishing feature was that the disk heads were not withdrawn completely from
8740-458: Was not sold under the drive manufacturer's name but under the subsystem manufacturer's name such as Corvus Systems and Tallgrass Technologies , or under the PC system manufacturer's name such as the Apple ProFile . The IBM PC/XT in 1983 included an internal 10 MB HDD, and soon thereafter, internal HDDs proliferated on personal computers. External HDDs remained popular for much longer on
8835-532: Was paid in cash and the rest with 25 million shares of Western Digital. In 2011, Western Digital established an R&D facility at its Malaysian plant at a cost of 1.2 billion US dollars. In March 2012, Western Digital completed the acquisition of HGST and became the largest traditional hard drive manufacturer in the world. To address the requirements of regulatory agencies, in May 2012 Western Digital divested assets to manufacture and sell certain 3.5-inch hard drives for
8930-409: Was sold to Philips , and since disappeared. Its networking and floppy drive controller divisions went to SMC Networks and its SCSI chip business went to Future Domain , which was later bought out by market leader Adaptec . Around 1995, the technological lead that the Caviar drives had enjoyed was eclipsed by newer offerings from other companies, especially Quantum Corp. , and Western Digital fell into
9025-408: Was the norm. As of November 2019 , the platters in most consumer-grade HDDs spin at 5,400 or 7,200 rpm. Information is written to and read from a platter as it rotates past devices called read-and-write heads that are positioned to operate very close to the magnetic surface, with their flying height often in the range of tens of nanometers. The read-and-write head is used to detect and modify
#813186