The History of the Hard Disk Drive

With a history spanning more than sixty years, the hard disk drive has maintained its position as one of the dominant data storage devices in use today.

The hard disk drive (HDD) is a mechanical data storage device that stores data on one or more spinning magnetic platters, paired with read/write heads on a moving actuator arm that reads data from and writes data to the platters. More than sixty years on, hard drives are virtually unrecognisable from the very first models. The IBM 305 RAMAC was the first commercial computer that stored data on a moving-head hard disk drive, publicly unveiled in 1956, known as the IBM 305 Disk File. The IBM 305 was the size of two large fridges, weighed over a tonne and stored just 5MB of data, at a cost of $10,000 per megabyte. June 1961 saw the release of the IBM 1301 Disk Storage Unit, which was notable for featuring a separate arm and head for each recording surface, significantly reducing maximum access times. The IBM 1301 was also the first hard drive to use heads that floated on a thin layer of air, which allowed them to be closer to the recording surface, improving efficiency massively. The 1301 – like all of the early hard drives – was incredibly expensive – it could be leased for $2,100 a month, or purchased for $115,500. The drive’s capacity was drastically increased, offering up to 205 MB, depending on the number of platters installed. The IBM 1302, introduced in 1963, offered further improvements. The capacity was quadrupled, and the data transfer speed was more than double that of its predecessor.

IBM produced the 3380 in 1980, the world’s first gigabyte capacity HDD, with 2.5GB of storage. However, the cost was still incredibly high - $40,000. In addition to the high cost, the drive also weighed more than 500lbs. The 1980s saw the introduction of the PC, with manufacturers like Hewlett-Packard manufacturing hard drives compatible with minicomputers. However, hard disk drives for use in PCs was initially quite rare, due the still incredibly high cost – Hewlett-Packard’s 7935 HDD cost around $27,000. PCs typically utilised floppy disks or cassette tape drives, both as secondary storage and as transport media; by the late 1980s, hard disk drives had decreased in cost and were standard on most PCs. Hard disk drives continued to get smaller, with the introduction of the 3.5-inch drive in 1988, which emerged as the dominant HDD by the 1990s. Throughout the 1990s, hard drives continued to sell more units, and decrease in size – IBM released the Microdrive in 1988, with 340GB of data stored on a single 1-inch platter. 2003 saw Seagate release the first SATA drive, and Hitachi bought IBM’s data storage division the same year. In the last fifteen years, the focus has been on storage capacity. Hitachi manufactured the world’s first 500GB hard disk drive in 2005, and the first terabyte HDD two years later. By 2010, Seagate and Western Digital were manufacturing hard drives with capacities of 3TB.

Today, most hard drives are produced by just three manufacturers – Western Digital, Seagate and Toshiba (Hitachi and Fujitsu were acquired by Western Digital and Toshiba, respectively). The latest innovation in hard disk drive technology is helium filled HDDs, which allow more data to be stored on each platter. Western Digital released a helium filled HDD with a whopping 12TB of storage across eight platters, under their commercial-orientated HGST brand. The 2010s saw the continued decline of hard disk drive sales and gradual increase of solid-state drives, which offer higher speeds and increased durability, due to their lack of moving parts. Where SSDs can’t yet compete, however, is storage capacity, so the humble HDD won’t be disappearing any time soon.

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