A ____ Is a Separate Piece of Hardware Containing Multiple High-speed Hard Drives.

What is a hard disk?

A computer difficult deejay bulldoze (HDD) is a non-volatile data storage device. Not-volatile refers to storage devices that maintain stored data when turned off. All computers demand a storage device, and HDDs are just one example of a type of storage device.

HDDs are ordinarily installed inside desktop computers, mobile devices, consumer electronics and enterprise storage arrays in data centers. They can store operating systems, software programs and other files using magnetic disks.

More than specifically, hard deejay drives control the reading and writing of the hd that provides data storage. HDDs are used either as the primary or secondary storage device in a computer. They are commonly constitute in the drive bay and are continued to the motherboard via an Avant-garde Technology Zipper (ATA), Serial ATA, parallel ATA or Small Computer System Interface (SCSI) cablevision, amid other formats. The HDD is besides connected to a power supply unit of measurement and can go along stored data while powered downwards.

A hd drive -- often shortened to difficult drive -- and difficult deejay are not the same things, simply they are packaged as a unit and either term can refer to the whole unit.

Why practise computers need difficult disks?

Storage devices like hard disks are needed to install operating systems, programs and additional storage devices, and to save documents. Without devices like HDDs that can retain data afterwards they have been turned off, computer users would not be able to shop programs or relieve files or documents to their computers. This is why every computer needs at least ane storage device to permanently agree data as long equally it is needed.

How do hard disk drives work?

Virtually basic hard drives consist of several disk platters -- a circular disk made of either aluminum, glass or ceramic -- that are positioned around a spindle within a sealed chamber. The platter spins with a motor that is connected to the spindle. The chamber also includes the read/write heads that magnetically record information to and from tracks on the platters using a magnetic caput. The disks also have a thin magnetic coating on them.

The motor spins the platters at up to 15,000 rotations per infinitesimal. Equally the platters spin, a 2d motor controls the position of the read and write heads that magnetically tape and read information on each platter.

Hard disk storage capacity

Some of the about common storage drive capacities include the following:

16 GB , 32 GB and 64 GB. This range is among the lowest for HDD storage space and is typically found in older and smaller devices.
120 GB and 256 GB. This range is more often than not considered an entry point for HDD devices such equally laptops or computers.
500 GB, 1 TB and ii TB. Around 500 GB and above of HDD storage is typically considered decent for an average user. Users can most likely store all their music, photos, videos and other files with this much space. Individuals with games that take up a lot of space should find ane TB to 2 TB of HDD space suitable.
More than ii TB. Anything over ii TB of HDD space is suitable for users who work with high-resolution files, who need to store or house a big amount of data, or who want to use that space for backup and back-up.

Currently, the highest capacity HDD is 20 TB. Yet, an HDD really has less space than advertised, as the operating system, file system structures and some data redundancy procedures use a portion of that space.

Hard drive components and form factors

Hard disk drive components include the spindle, disk platter, actuator, actuator arm and read/write head. Even though the term can refer to the unit of measurement equally a whole, the term hard disk is the set of stacked disks -- in other words, the function of the HDD that stores and provides admission to information on an electromagnetically charged surface.

The HDD class factor refers to the concrete size or geometry of the data storage device. HDD grade factors follow a set up of industry standards that govern their length, width and height, every bit well as the position and orientation of the host interface connector. Having an manufacture-standard form factor helps make up one's mind a common compatibility with different computing devices.

The most mutual course factors for HDDs in enterprise systems are 2.5-inch and iii.five-inch -- too known as small course cistron (SFF) and large form factor (LFF). The ii.5-inch and three.5-inch measurements stand for the approximate diameter of the platter within the drive enclosures.

While there are other form factors, by 2009, manufacturers discontinued the development of products with one.3-inch, one-inch and 0.85-inch grade factors. The falling price of flash made these other form factors almost obsolete. It is also of import to note that while nominal sizes are in inches, bodily dimensions are specified in millimeters.

Many solid-state drives (SSDs) are too designed for the HDD class factor. SSDs that fit into the same slots every bit HDDs mostly use the SATA or serial-attached SCSI (SAS) interface to transfer information to and from the host computing organisation.

What are external HDDs?

Most HDDs are found internally in a reckoner and work equally stated above. However, individuals tin can besides purchase external hard drives. External hard drives can exist used to expand the storage chapters of a computer or to deed as a portable device to dorsum up data. External drives connect to a figurer or device through interfaces like USB 2.0, USB-C or with External SATA (eSATA). External hard drives may also have slower data transfer rates compared to internal HDDs.

The primary reward of an external difficult drive, aside from beingness able to expand a device's storage space, includes being portable. Users can store information from multiple devices and physically bring that data with them wherever they become.

Mutual hard disk drive errors

Hard disks can fail for all sorts of reasons. However, failures more often than not fall into the following six broad categories.

Electrical failure occurs when, for example, a ability surge damages a hard disk's electronic circuitry, causing the read/write head or circuit board to neglect. If a hard disk powers on only cannot read and write data or kick, it is likely that one or more than of its components has suffered an electrical failure.
Mechanical failure can be acquired past wear and tear, besides equally by a hard touch, like a hard drop. This may cause, among other things, the read/write drive caput to hit a rotating platter, causing irreversible physical impairment.
Logical failure results when the hd's software is compromised or ceases to run properly. All sorts of data corruption can lead to a logical failure. This includes corrupted files, malware and viruses, improperly endmost an application or shutting downward a computer, human error or accidentally deleting files that are disquisitional to hard disk functionality.
Bad sector failure can occur when the magnetic media on a hard disk's rotating platter is misaligned, resulting in a specific expanse on the platter becoming inaccessible. Bad sectors are common and often limited when they occur. Over time, however, the number of bad sectors can increment, eventually leading to a system crash, inaccessible files or the hanging or lagging of the performance of a hard deejay.
Firmware failure happens when the software that performs the maintenance tasks on a drive and enables the hd to communicate with a calculator becomes corrupted or stops working properly. This type of failure can lead to the disk freezing during bootup or the calculator a hard deejay is connected to not recognizing or misidentifying it.
Multiple unknown failures that accumulate over time can also occur. For example, an electrical problem could lead to a mechanical failure, such as a read/write head crash. It might also lead to a logical failure, resulting in several bad sectors developing on the hard disk platters.

History of hard disk drives

The hd was created in 1953 by engineers at IBM who wanted to discover a way to provide random access to high capacities of data at a low cost. The disk drives developed were the size of refrigerators, could shop iii.75 MB of data and began shipping in 1956. Memorex, Seagate Applied science and Western Digital were other early on vendors of hard disk drive technology.

Hard disk form-factor size has connected to decrease every bit the technology evolves. By the mid-1980s, three.five-inch and 2.5-inch form factors were introduced and became a standard in personal computers.

Hard disk drive density has increased since the technology was outset developed. The showtime difficult disk drives could shop megabytes of information, while today their storage capacity is in the terabyte range. Hitachi Global Storage Technologies ( HGST ) -- now a Western Digital make -- released the first 1 TB difficult drives in 2007. In 2015, HGST announced the first 10 TB difficult drive. And in 2021, Western Digital unveiled two xx TB HDDs.

HDD evolution and technology developments

In 2013, Seagate Technology appear hard deejay drives that utilise shingled magnetic recording (SMR) technology. SMR increases storage density in hard disk drives by layering the magnetic tracks on each disk, rather than placing them parallel to each other. It is referred to every bit shingled considering the tracks overlap similar to shingles on a roof.

Hard disk drive components. — This image shows what a hard drive looks like with its internal components.

HGST announced the get-go helium-filled hard disk drive drive in 2012. Helium is less dense, cooler and lighter than air, consumes less power, increases bulldoze density and improves functioning compared to traditional hd drives. In 2016, Seagate appear its own ten TB helium hard drive.

In 2021, drive manufacturer Western Digital unveiled two 20 TB HDDs -- the Ultrastar DC HC560 and WD Gilded HDD Enterprise Course SATA HDD. Currently, 20 TB is the largest bachelor HDD size. Both hard disk drive drives come in the standard 3.v-inch form factor simply accept different use cases. The Ultrastar DC HC560 is meant for cloud storage providers and for business concern servers, security systems and network-attached storage devices. The WD Gilt HDD is designed for enterprise businesses that run heavy application workloads.

HDDs vs. SSDs

The main alternative to hd drives are solid-state drives.

Dissimilar hard disks, SSDs contain no moving parts. SSDs also accept lower latency than HDDs, and therefore are frequently favored to shop critical information that needs to be accessed quickly and for applications with a high input/output demand. SSDs are configured to deliver high read/write speeds for sequential and random data requests. Additionally, SSDs do not store data magnetically, so the read performance remains steady, regardless of where the information is stored on the drive. SSDs also have faster kick times.

It is considering of these benefits, and that HDDs are more vulnerable to breakdowns, that HDDs are now starting to be replaced by SSDs.

However, even though well-nigh PC users have started to favor SSDs, HDDs -- along with magnetic tape -- are still used frequently to shop large amounts of data. In role, this is because SSDs are more expensive than HDDs from a toll-per-gigabyte standpoint. Many enterprise storage arrays send with a mix of HDDs and SSDs to reduce costs while providing better performance. SSDs likewise have a set life expectancy, with a finite number of write cycles before functioning slows. Compared to an HDD, SSDs fail faster.

Learn more about how SSDs compare to HDDs in this article.

This was last updated in December 2021

Continue Reading Nigh hd (HDD)

Western Digital OptiNAND stretches HDD chapters, performance

Hyperscale shift to eighteen TB, SMR HDDs superlative '21 difficult disk trends

Seagate debuts NVMe HDD engineering at OCP

QLC flash drives are hot '21 trend, pressure HDDs on price

Flash-native architectures power next-generation real-time workloads

Dig Deeper on Main storage devices

Hard disk drive drives to remain ascendant storage media in 2022

By: Adam Armstrong
Western Digital OptiNAND stretches HDD chapters, operation

Past: Johnny Yu
New Seagate Exos storage uses cocky-healing drive technology

Past: Carol Sliwa
Hyperscale shift to 18 TB, SMR HDDs height '21 hd trends

By: Carol Sliwa