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Active Hard-drive Protection
In computer hardware, active hard-drive protection refers to technology that attempts to avoid or reduce mechanical damage to hard disk drives by preparing the disk prior to impact. This approach is mainly used in laptop computers that are frequently carried around and more prone to impacts than desktop computers. Implementation Usually, the system consists of accelerometers that alert the system when excess acceleration or vibration is detected. The software then tells the hard disk drive to unload its heads to prevent them from coming in contact with the platters, thus potentially preventing a head crash. Many laptop vendors have implemented this technology under different names. Some hard-disk drives also include this technology, needing no cooperation from the system. See also * Hard disk drive failure * Head crash * Sudden Motion Sensor The Sudden Motion Sensor (SMS) is Apple's motion-based data protection system used in their notebook computer systems. Apple introduce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 hard disk drive platter, platters coated with magnetic material. The platters are paired with disk read-and-write head, 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 Block (data storage), 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 disk enclosure, rectangular box. Hard disk drives were introduced by IBM in 1956, and were the dominant secondary storage device for History of general-purpose CPUs, general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laptop Computer
A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer screen, screen on the inside of the upper lid and an alphanumeric keyboard and pointing device on the inside of the lower lid. Most of the computer's internal hardware is in the lower part, under the keyboard, although many modern laptops have a built-in webcam at the top of the screen, and some even feature a touchscreen display. In most cases, unlike tablet computers which run on mobile operating systems, laptops tend to run on desktop operating systems, which were originally developed for desktop computers. Laptops are used in a variety of settings, such as at work (especially on business trips), in education, for PC game, playing games, Content creation, content creating, web browser, web browsing, for personal multimedia, and for general P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desktop Computer
A desktop computer, often abbreviated as desktop, is a personal computer designed for regular use at a stationary location on or near a desk (as opposed to a portable computer) due to its size and power requirements. The most common configuration has a computer case, case that houses the power supply unit (computer), power supply, motherboard (a printed circuit board with a microprocessor as the central processing unit, computer memory, memory, bus (computing), bus, certain peripherals and other electronic components), disk storage (usually one or more hard disk drives, solid-state drives, optical disc drives, and in early models floppy disk drives); a computer keyboard, keyboard and computer mouse, mouse for input (computer science), input; and a computer monitor, monitor, computer speakers, speakers, and, often, a printer (computing), printer for output. The case may be oriented horizontally or vertically and placed either underneath, beside, or on top of a desk. Desktop Comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerometer
An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration (the rate of change (mathematics), rate of change of velocity) of the object relative to an observer who is in free fall (that is, relative to an inertial frame of reference). Proper acceleration is different from coordinate acceleration, which is acceleration with respect to a given coordinate system, which may or may not be accelerating. For example, an accelerometer at rest on the surface of the Earth will measure an Gravitational acceleration, acceleration due to Earth's gravity straight upwards of about Standard gravity, ''g'' ≈ 9.81 m/s2. By contrast, an accelerometer that is in free fall will measure zero acceleration. Accelerometers have many uses in industry, consumer products, and science. Highly sensitive accelerometers are used in inertial navigation systems for aircraft and missiles. In unmanned aerial vehicles, accelerometers help to stabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Read-write Head
A disk read-and-write head is the small part of a disk drive that moves above the disk platter and transforms the platter's magnetic field into electric current (reads the disk) or, vice versa, transforms electric current into magnetic field (writes the disk). The heads have gone through a number of changes over the years. In a hard drive, the heads ''fly'' above the disk surface with clearance of as little as 3 nanometres. The flying height has been decreasing with each new generation of technology to enable higher areal density. The flying height of the head is controlled by the design of an air bearing etched onto the disk-facing surface of the ''slider''. The role of the air bearing is to maintain the flying height constant as the head moves over the surface of the disk. The air bearings are carefully designed to maintain the same height across the entire platter, despite differing speeds depending on the head distance from the center of the platter. If the head hit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard-disk Platter
A hard disk drive platter or hard disk is the circular magnetic disk on which digital data is stored in a hard disk drive. The rigid nature of the platters is what gives them their name (as opposed to the flexible materials which are used to make floppy disks). Hard drives typically have several platters which are mounted on the same spindle. A platter can store information on both sides, typically requiring two recording heads per platter, one per surface. Design The magnetic surface of each platter is divided into small sub-micrometer-sized magnetic regions, each of which is used to represent a single binary unit of information. A typical magnetic region on a hard-disk platter (as of 2006) is about 200–250 nanometers wide (in the radial direction of the platter) and extends about 25–30 nanometers in the down-track direction (the circumferential direction on the platter), corresponding to about 100 billion bits per square inch of disk area (15.5 Gbit/cm2). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head Crash
A head crash is a hard-disk failure that occurs when a disk read-and-write head, read–write head of a hard disk drive makes contact with its rotating hard disk platter, platter, slashing its surface and permanently damaging its magnetic media. It is difficult to recover data from a head crashed drive. It is most often caused by a sudden severe motion of the disk, for example the jolt caused by dropping a laptop to the ground while it is operating or physically shocking a computer. Laptop 2.5 drives are significantly more likely to have a head crash due to their mobile nature despite having higher shock resistance than 3.5 desktop drives. Desktop drives being larger are more prone to damage if dropped but are usually in one place like in a computer/server so they are overall less likely to have a head crash. Head details A head normally rides on Air bearing, a thin film of moving air entrapped at the surface of its platter (some drives manufactured by Conner Peripherals in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AnandTech
''AnandTech'' was an online computer hardware magazine owned by Future plc. It was founded in April 1997 by then-14-year-old Anand Lal Shimpi, who was CEO and editor-in-chief until August 2014, with Ryan Smith replacing him as editor-in-chief. The website was a source of hardware reviews for off-the-shelf components and exhaustive benchmarking, targeted towards computer-building enthusiasts, but later expanded to cover mobile devices such as smartphones and tablets. Some of their articles on mass-market products such as mobile phones were syndicated by CNNMoney. The large accompanying forum is recommended by some books for bargain hunting in the technology field. AnandTech was acquired by Purch on 17 December 2014. Purch was acquired by Future in 2018. On August 30, 2024, the publication shut down. The content of the website was said to be preserved, but no new articles or reviews would be published. The AnandTech forums would continue to operate. History In its early s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk Drive Failure
A hard disk drive failure occurs when a hard disk drive malfunctions and the stored information cannot be accessed with a properly configured computer. A hard disk failure may occur in the course of normal operation, or due to an external factor such as exposure to fire or water or high magnetic fields, or suffering a sharp impact (mechanics), impact or environmental contamination, which can lead to a head crash. The stored information on a hard drive may also be rendered inaccessible as a result of data corruption, disruption or destruction of the hard drive's master boot record, or by malware deliberately destroying the disk's contents. Causes There are a number of causes for hard drives to fail including: human error, hardware failure, firmware corruption, media damage, heat, water damage, power issues and mishaps. Drive manufacturers typically specify a mean time between failures (MTBF) or an annualized failure rate (AFR) which are population statistics that can't predict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head Crash
A head crash is a hard-disk failure that occurs when a disk read-and-write head, read–write head of a hard disk drive makes contact with its rotating hard disk platter, platter, slashing its surface and permanently damaging its magnetic media. It is difficult to recover data from a head crashed drive. It is most often caused by a sudden severe motion of the disk, for example the jolt caused by dropping a laptop to the ground while it is operating or physically shocking a computer. Laptop 2.5 drives are significantly more likely to have a head crash due to their mobile nature despite having higher shock resistance than 3.5 desktop drives. Desktop drives being larger are more prone to damage if dropped but are usually in one place like in a computer/server so they are overall less likely to have a head crash. Head details A head normally rides on Air bearing, a thin film of moving air entrapped at the surface of its platter (some drives manufactured by Conner Peripherals in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudden Motion Sensor
The Sudden Motion Sensor (SMS) is Apple's motion-based data protection system used in their notebook computer systems. Apple introduced the system January 1, 2005 in its refreshed PowerBook line, and included it in the iBook line July 26, 2005. Since that time, Apple has included the system in all of their non-SSD portable systems (since October 2006), now the MacBook Pro and MacBook Air. With a triaxial accelerometer, the shock detector detects sudden acceleration, such as when the computer is dropped, and prepares the relatively fragile hard disk drive mechanism for impact. The system disengages the disk drive heads from the hard disk platters, preventing data loss and drive damage from a disk head crash. When the computer is stable, the drive operates normally again. A clicking noise can be heard when the sudden motion sensor activates. Broadly speaking, there have been two types of Sudden Motion Sensor. The sensor used in the G4-based laptops resolved shifts of 1/52 g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Security
Data security or data protection means protecting digital data, such as those in a database, from destructive forces and from the unwanted actions of unauthorized users, such as a cyberattack or a data breach. Technologies Disk encryption Disk encryption refers to encryption technology that encrypts data on a hard disk drive. Disk encryption typically takes form in either software (see disk encryption software) or hardware (see disk encryption hardware). Disk encryption is often referred to as on-the-fly encryption (OTFE) or transparent encryption. Software versus hardware-based mechanisms for protecting data Software-based security solutions encrypt the data to protect it from theft. However, a malicious program or a hacker could corrupt the data to make it unrecoverable, making the system unusable. Hardware-based security solutions prevent read and write access to data, which provides very strong protection against tampering and unauthorized access. Hardware- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
