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 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.
Western Digital Corporation is an American computer drive manufacturer and data storage company, headquartered in San Jose, California. It designs, manufactures and sells data technology products, including data storage devices, data center systems and cloud storage services.
Seagate Technology Holdings plc is an American data storage company. It was incorporated in 1978 as Shugart Technology and commenced business in 1979. Since 2010, the company has been incorporated in Dublin, Ireland, with operational headquarters in Fremont, California, United States.
IBM manufactured magnetic disk storage devices from 1956 to 2003, when it sold its hard disk drive business to Hitachi. Both the hard disk drive (HDD) and floppy disk drive (FDD) were invented by IBM and as such IBM's employees were responsible for many of the innovations in these products and their technologies. The basic mechanical arrangement of hard disk drives has not changed since the IBM 1301. Disk drive performance and characteristics are measured by the same standards now as they were in the 1950s. Few products in history have enjoyed such spectacular declines in cost and physical size along with equally dramatic improvements in capacity and performance.
Density is a measure of the quantity of information bits that can be stored on a given physical space of a computer storage medium. There are three types of density: length of track, area of the surface, or in a given volume.
The Western Digital Raptor is a discontinued series of high performance hard disk drives produced by Western Digital first marketed in 2003. The drive occupied a niche in the enthusiast, workstation and small-server market. Traditionally, the majority of servers used hard drives featuring a SCSI interface because of their advantages in both performance and reliability over consumer-level ATA drives.
The Microdrive is a type of miniature, 1-inch hard disk produced by IBM and Hitachi. These rotational media storage devices were designed to fit in CompactFlash (CF) Type II slots.
Perpendicular recording, also known as conventional magnetic recording (CMR), is a technology for data recording on magnetic media, particularly hard disks. It was first proven advantageous in 1976 by Shun-ichi Iwasaki, then professor of the Tohoku University in Japan, and first commercially implemented in 2005. The first industry-standard demonstration showing unprecedented advantage of PMR over longitudinal magnetic recording (LMR) at nanoscale dimensions was made in 1998 at IBM Almaden Research Center in collaboration with researchers of Data Storage Systems Center (DSSC) – a National Science Foundation (NSF) Engineering Research Center (ERCs) at Carnegie Mellon University (CMU).
A hybrid drive is a logical or physical computer storage device that combines a faster storage medium such as solid-state drive (SSD) with a higher-capacity hard disk drive (HDD). The intent is adding some of the speed of SSDs to the cost-effective storage capacity of traditional HDDs. The purpose of the SSD in a hybrid drive is to act as a cache for the data stored on the HDD, improving the overall performance by keeping copies of the most frequently used data on the faster SSD drive.
The Quantum Bigfoot brand was a series of hard disk drives produced by Quantum Corp. from 1996 through the late 1990s. The Bigfoot series was notable for deviating from the standard form factor for hard drives. While most desktop hard drives at that time used a 3.5-inch physical format, Quantum Bigfoot drives used a larger 5.25-inch form factor more commonly seen in older hard drives, CD-ROM and other optical disc drives. This form factor allowed Quantum to increase the capacity of their hard drives without an increase in data density, thus lowering costs compared to a 3.5-inch drive with the same capacity. It also allowed manufacturers and owners to install the hard drive above or below the optical drive in the computer, as the typical computer had multiple 5.25-inch bays.
Deskstar was the name of a product line of computer hard disk drives. It was originally announced by IBM in October 1994. The line was continued by Hitachi, when in 2003 it bought IBM's hard disk drive division and renamed it Hitachi Global Storage Technologies. In 2012, Hitachi sold the division to Western Digital, who continued the drive product line brand as HGST Deskstar. In 2018, Western Digital began winding down the HGST brand, and as of 2020 it is defunct.
HGST, Inc. was a manufacturer of hard disk drives, solid-state drives, and external storage products and services.
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. After considering technologies such as wire matrices, rod arrays, drums, drum arrays, etc., the engineers at IBM's San Jose California laboratory invented the hard disk drive. 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 but faster and more expensive than tape drives.
A solid-state drive (SSD) is a type of solid-state storage device that uses integrated circuits to store data persistently. It is sometimes called semiconductor storage device, solid-state device, and solid-state disk.
The Seagate Barracuda is a series of hard disk drives and later solid state drives produced by Seagate Technology that was first introduced in 1993.
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: access time and data transfer time .
Shingled magnetic recording (SMR) is a magnetic storage data recording technology used in hard disk drives (HDDs) to increase storage density and overall per-drive storage capacity. Conventional hard disk drives record data by writing non-overlapping concentric magnetic tracks, while shingled recording writes new tracks that overlap part of the previously written magnetic track, leaving the previous track narrower and allowing higher track density. Thus, the tracks partially overlap similar to roof shingles. This approach was selected because, if the writing head is made too narrow, it cannot provide the very high fields required in the recording layer of the disk.
The Quantum Fireball was a brand of 3.5-inch hard disk drives made by Quantum Corporation from 1995 to 2001. The first models in the series were 5400 RPM and came in 0.54 and 1.08 GB capacities, while the Quantum Fireball Plus was known for being Quantum's first 7200 RPM Integrated Drive Electronics (IDE) hard drive. There were sixteen different models of the Quantum Fireball, with the last being the LCT 20.
Ultrastar is a Western Digital brand of high performance 3.5-inch hard disk drives (HDDs) and solid-state drives (SSDs).
