Since the invention of the floppy disk drive, various standardized form factors have been used in computing systems. Standardized form factors and interface allow a variety of peripherals and upgrades thereto with no impact to the physical size of a computer system. Drives may slot into a drive bay of the corresponding size.
Compared to flash drives in same form factor, maximum rotating disk drive capacity is much smaller,[citation needed] with 100 TB available in 2018[update],[1] and 32 TB for 2.5-inch.[2]
List
editForm factor (inch) |
Status | Dimensions (Dimension in inches unless otherwise noted) |
Largest capacity | Platters (max.) | Capacity per platter (GB) | ||
---|---|---|---|---|---|---|---|
Length | Width | Height | |||||
3.5 | Current | 5.75 | 4.0 | 18.28mm,[3] 26.11 mm[4] or 19.99 mm[5] | 32 TB (January 2024)[6][7] | 10[8] (June 2022)[9] | 3,000[10] |
2.5 | Current | 4.0 | 2.75 | 5,[11] 7, 9.5,[a] 12.5, 15 or 19[12] (all mm) |
6 TB[13][14][15][16] (May 2024) | 6[17] | 1,000 |
1.8 | Obsolete | 78.5 mm,[b] 71 mm[c] | 54 mm | 5 mm[18] or 8 mm | 320 GB[19] (2009) | 2 | 220[20] |
8 | Obsolete | 14.5 | 9.5 | 4.625 | 2.0 GB (1989)[21][22] | Unknown (at least 12) |
Unknown (at least 0.16) |
5.25 (FH) | Obsolete | 8.0 | 5.75 | 3.25 | 47 GB[23] (1998) | 14 | 3.36 |
5.25 (HH) | Obsolete | 8.0 | 5.75 | 1.625 | 19.3 GB[24] (1998) | 4[d] | 4.83 |
1.3 | Obsolete | 50.8 mm[25] | 36.5 mm[25] | 10.5 mm[25] | 40 GB[26] (2007) | 1 | 40 |
1 (CFII/ZIF/IDE-Flex, "Microdrive") | Obsolete | 42.8 mm | 36.4 mm | 5 mm | 20 GB (2006) | 1 | 20 |
0.85 | Obsolete | 32 mm | 24 mm | 5 mm | 8 GB[27][28] (2004) | 1 | 8 |
IBM's first hard drive, the IBM 350, used a stack of fifty 24-inch platters and was of a size comparable to two large refrigerators. In 1962, IBM introduced its model 1311 disk, which used six 14-inch (nominal size) platters in a removable pack and was roughly the size of a washing machine. This became a standard platter size and drive form-factor for many years, used also by other manufacturers. The IBM 2314 used platters of the same size in an eleven-high pack and introduced the "drive in a drawer" layout, although the "drawer" was not the complete drive.
Later drives were designed to fit entirely into a chassis that would mount in a 19-inch rack. Digital's RK05 and RL01 were early examples using single 14-inch platters in removable packs, the entire drive fitting in a 10.5-inch-high rack space (six rack units). In the mid-to-late 1980s the similarly sized Fujitsu Eagle, which used (coincidentally) 10.5-inch platters, was a popular product.
Such large platters were never used with microprocessor-based systems.[citation needed] With increasing sales of microcomputers having built in floppy-disk drives (FDDs), HDDs that would fit to the FDD mountings became desirable. Thus HDD Form factors, initially followed those of 8-inch, 5.25-inch, and 3.5-inch floppy disk drives. Because there were no smaller floppy disk drives, smaller HDD form factors developed from product offerings or industry standards.
8-inch
edit9.5 in × 4.624 in × 14.25 in (241.3 mm × 117.5 mm × 362 mm). In 1979, Shugart Associates' SA1000 was the first form factor compatible HDD, having the same dimensions and a compatible interface to the 8" FDD.
5.25-inch
edit5.75 in × 3.25 in × 8 in (146.1 mm × 82.55 mm × 203 mm). This smaller form factor, first used in an HDD by Seagate in 1980, was the same size as full-height 5+1⁄4-inch-diameter (130 mm) FDD, 3.25-inches high. This is twice as high as "half height"; i.e., 1.63 in (41.4 mm). Most desktop models of drives for optical 120 mm disks (DVD, CD) use the half height 5¼" dimension, but it fell out of fashion for HDDs. The format was standardized as EIA-741 and co-published as SFF-8501 for disk drives, with other SFF-85xx series standards covering related 5.25 inch devices (optical drives, etc.)[29] The Quantum Bigfoot HDD was the last to use it in the late 1990s, with "low-profile" (≈25 mm) and "ultra-low-profile" (≈20 mm) high versions.
3.5-inch
edit4 in × 1 in × 5.75 in (101.6 mm × 25.4 mm × 146 mm) = 376.77344 cm³. This smaller form factor is similar to that used in an HDD by Rodime in 1983, which was the same size as the "half height" 3½" FDD, i.e., 1.63 inches high. Today, the 1-inch high ("slimline" or "low-profile") version of this form factor is the most popular form used in most desktops. The format was standardized in terms of dimensions and positions of mounting holes as EIA/ECA-740, co-published as SFF-8301.[30] At least Seagate made 19.99-mm-high drives too.[5] At least Samsung made a low-profile single-disc drive with a height of only 18.288 mm (0.72 in).[3]
2.5-inch
edit2.75 in × 0.197–0.75 in × 3.945 in (69.85 mm × 5–19 mm × 100 mm) = 34.925–132.715 cm3. This smaller form factor was introduced by PrairieTek in 1988; there is no corresponding FDD. The 2.5-inch drive format is standardized in the EIA/ECA-720 co-published as SFF-8201; when used with specific connectors, more detailed specifications are SFF-8212 for the 50-pin (ATA laptop) connector, SFF-8223 with the SATA, or SAS connector and SFF-8222 with the SCA-2 connector.[31]
It came to be widely used for HDDs in mobile devices (laptops, music players, etc.) and for solid-state drives (SSDs), by 2008 replacing some 3.5 inch enterprise-class drives. It is also used in the PlayStation 3 and Xbox 360[32] video game consoles.
Drives 9.5 mm high became an unofficial standard for all except the largest-capacity laptop drives (usually having two platters inside); 12.5 mm-high drives, typically with three platters, are used for maximum capacity, but will not fit most laptop computers. Enterprise-class drives can have a height up to 15 mm. Seagate released a 7 mm drive aimed at entry level laptops and high end netbooks in December 2009. Western Digital released on April 23, 2013 a hard drive 5 mm in height specifically aimed at Ultrabooks.[33]
1.8-inch
edit54 mm × 8 mm × 78.5 mm[b] = 33.912 cm³. This form factor, originally introduced by Intégral Peripherals in 1991, evolved into the ATA-7 ZIF with dimensions as stated but with a total length of 71mm. Later, the micro-SATA interface made the total length 78.5mm.
1.8-inch drives with ZIF connectors were used in digital audio players, such as the iPod Classic, and subnotebooks. Later 1.8-inch drives were updated with a micro-SATA connector and up to 320GB of storage (Toshiba MK3233GSG). The 1.8-inch form factor was eventually phased out as SSDs became cheaper and more compact.[34] There was an attempt to standardize this format as SFF-8123, but it was cancelled in 2005.[35] SATA revision 2.6 standardized the internal Micro SATA connector and device dimensions.
1.3-inch
edit51 mm × 43.8 mm × 10.5 mm. This form factor was used by HP C3013A, C3013B and C3014A, named HP Kittyhawk microdrive, introduced in June 1992.
1-inch
edit42.8 mm × 5 mm × 36.4 mm. This form factor was introduced in 1999, as IBM's Microdrive to fit inside a CF Type II slot. Samsung calls the same form factor "1.3 inch" drive in its product literature.
0.85-inch
edit24 mm × 5 mm × 32 mm. Toshiba announced this form factor in January 2004 for use in mobile phones and similar applications, including SD/MMC slot compatible HDDs optimized for video storage on 4G handsets. Toshiba manufactured a 4 GB (MK4001MTD) and an 8 GB (MK8003MTD) version and holds the Guinness World Record for the smallest HDD.
Modern Usage
editAs of 2023[update], 2.5-inch and 3.5-inch hard disks are the most popular sizes.
By 2009, all manufacturers had discontinued the development of new products for the 1.3-inch, 1-inch and 0.85-inch form factors due to falling prices of flash memory, which has no moving parts.[citation needed]
While these sizes are customarily described by an approximately correct figure in inches, actual sizes have long been specified in millimeters. The older 3.5-inch form factor uses UNC threads, while 2.5-inch drives use metric M3 threads.
Notes
edit- ^ Most common
- ^ a b This dimension includes a 0.5 mm protrusion of the Micro SATA connector from the device body.
- ^ Measured on Toshiba MK1011GAH
- ^ The Quantum Bigfoot TS used a maximum of three platters, other earlier and lower capacity product used up to four platters in a 5.25-inch HH form factor, e.g., Microscience HH1090 circa 1989.
References
edit- ^ "Dude, Here's Your 100TB Flash Drive!". Architecting IT. 2018-03-20. Archived from the original on 2020-08-12. Retrieved 2020-09-17.
- ^ Chen, Sam. "Samsung Unveils 32TB SSD Leveraging 4th Gen 64-Layer 3D V-NAND". Custom PC Review. Archived from the original on 2020-09-17. Retrieved 2020-09-17.
- ^ a b "Samsung Spinpoint PL40 Product Specification Rev 1.4 (09-09-'03)" (PDF). 2003. Retrieved August 24, 2022.
- ^ "Seagate Exos X16 16TB HDD Review". 2019. Archived from the original on December 18, 2019. Retrieved January 30, 2020.
- ^ a b "Seagate Barracuda 7200.10 Data Sheet" (PDF). 2007. Retrieved December 18, 2020.
- ^ Exos Mozaic 3 Plus Model No: ST32TB00000
- ^ Seagate’s Breakthrough 30TB+ Hard Drives Ramp Volume, Marking an Inflection Point in the Storage Industry
- ^ "Ultrastar DC HC670". westerndigital.
- ^ "Western Digital Launched 22TB and 26TB Hard Drives".
- ^ "Seagate's Breakthrough 30TB+ Hard Drives Ramp Volume, Marking an Inflection Point in the Storage Industry". seagate.com. Retrieved May 16, 2024.
- ^ "Western Digital builds 5mm-thick hybrid hard drive, Ultrabook makers sign on early". Engadget. September 10, 2012. Archived from the original on January 2, 2013. Retrieved January 7, 2013.
- ^ "Quantum Go*Drive specifications". 4drives.com. Archived from the original on October 22, 2017. Retrieved May 22, 2014.
- ^ Western Digital My Passport portable external hard disk drive, 6 TB
- ^ Western Digital Unveils World’s Highest Capacity 2.5” Portable HDDs, Boosting Its Most Popular Product Portfolios
- ^ WD Debuts the First 6TB 2.5-inch Portable Hard Drive
- ^ WD’s large-capacity moveable laborious drives are again with new 6TB fashions
- ^ Not Dead Yet: WD Releases New 6TB 2.5-Inch External Hard Drives - First Upgrade in Seven Years
- ^ "MAXTOR 1.8" DRIVES FIT 5mm TYPE II PCMCIA SLOTS, RUN OFF 3.3V - Tech Monitor". October 14, 1994.
- ^ "Toshiba Storage Solutions – MK3233GSG". Archived from the original on 2012-07-24. Retrieved 2017-10-24.
- ^ "Toshiba MK2239GSL, 220 GB single-platter HDD" (PDF). Archived from the original (PDF) on 2014-02-23.
- ^ "FujitsuDriveList.txt". Archived from the original on 2017-12-19. Retrieved 2018-08-08.
- ^ "M2301 Magnetic Disk Unit". IPSJ Computer Museum. Archived from the original on 2018-11-05. Retrieved 2018-08-08.
- ^ Seagate Elite 47, shipped 12/97 per 1998 Disk/Trend Report – Rigid Disk Drives
- ^ Quantum Bigfoot TS, shipped 10/98 per 1999 Disk/Trend Report – Rigid Disk Drives
- ^ a b c HP Kittyhawk Personal Storage Modules Data Sheet, 1993
- ^ "SDK Starts Shipments of 1.3-Inch PMR-Technology-Based HD Media". Sdk.co.jp. January 10, 2008. Archived from the original on March 16, 2009. Retrieved March 13, 2009.
- ^ "Proving that 8 GB, 0.85 inch hard disk drive exists". Digitaljournal.com. February 17, 2007. Archived from the original on May 24, 2012. Retrieved April 26, 2012.
- ^ "Toshiba Enters Guinness World Records Book with the World's Smallest Hard Disk Drive". Toshiba Corp. March 16, 2004. Archived from the original on July 18, 2012. Retrieved September 11, 2012.
- ^ "SFF-8500 Specification for Suite of 5.25" Form Factor Specifications". SFF Committee. June 5, 1995. Retrieved 2024-10-10.
- ^ "SFF-8301 3.5" Form Factor Drive Dimensions" (PDF). SNIA SFF TA TWG. January 19, 2018. Archived from the original on December 23, 2018. Retrieved December 22, 2018.
- ^ "SFF-8201 Specification for Form Factor of 2.5" Disk Drives" (PDF). SFF Committee. October 28, 2013. Retrieved February 1, 2014.
- ^ "Xbox 360 HDD Replacement". July 31, 2010. Archived from the original on August 15, 2018. Retrieved March 9, 2016.
- ^ Ian Paul (April 23, 2013). "Western Digital rolls out ultra-slim 5 mm Ultrabook drives". PCWorld. Archived from the original on July 1, 2016. Retrieved October 24, 2017.
- ^ "World HDD Market: Key Research Findings 2010" (PDF). Yano Research Institute. December 15, 2010. Archived (PDF) from the original on March 2, 2013. Retrieved October 16, 2012.
- ^ "Specification for 1.8" (60x70mm) w/Serial Attachment Connector, Rev C" (PDF). SFF Committee. January 2005. Archived from the original on October 17, 2021. Retrieved February 1, 2014.