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Staggered Spinup
Spin-up refers to the process of a hard disk drive or optical disc drive accelerating its platters or inserted optical disc from a stopped state to an operational speed. The required operational speed depends on the design of the disk drive. Typical speeds of hard disks have been 2400, 3600, 4200, 5400, 7200, 10000 and 15000 revolutions per minute (RPM). Achieving such speeds can require a significant portion of the available power budget of a computer system, and so application of power to the disks must be carefully controlled. Operational speed of optical disc drives may vary depending on type of disc and mode of operation (see Constant linear velocity). Spin-up of hard disks generally occurs at the very beginning of the computer boot process. However, most modern computers have the ability to stop a drive while the machine is already running as a means of energy conservation or noise reduction. If a machine is running and requires access to a stopped drive, then a delay i ... [...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] |
SATA
SATA (Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard to become the predominant interface for storage devices. Serial ATA industry compatibility specifications originate from the Serial ATA International Organization (SATA-IO) which are then released by the INCITS Technical Committee T13, AT Attachment (INCITS T13). History SATA was announced in 2000 in order to provide several advantages over the earlier PATA interface such as reduced cable size and cost (seven conductors instead of 40 or 80), native hot swapping, faster data transfer through higher signaling rates, and more efficient transfer through an (optional) I/O queuing protocol. Revision 1.0 of the specification was released in January 2003. Serial ATA industry compatibility specifications originate from the Serial ATA Inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inrush Current
Inrush current, input surge current, or switch-on surge is the maximal instantaneous input current drawn by an electrical device when first turned on. Alternating-current electric motors and transformers may draw several times their normal full-load current when first energized, for a few cycles of the input waveform. Power converters also often have inrush currents much higher than their steady-state currents, due to the charging current of the input capacitance. The selection of over-current-protection devices such as fuses and circuit breakers is made more complicated when high inrush currents must be tolerated. The over-current protection must react quickly to overload or short-circuit faults but must not interrupt the circuit when the (usually harmless) inrush current flows. Capacitors A discharged or partially charged capacitor appears as a short circuit to the source when the source voltage is higher than the potential of the capacitor. A fully discharged capacitor will tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Attached SCSI
In computing, Serial Attached SCSI (SAS) is a point-to-point serial Communications protocol, protocol that moves data to and from Computer storage, computer-storage devices such as hard disk drives, solid-state drives and tape drives. SAS replaces the older Parallel SCSI (Parallel Small Computer System Interface, usually pronounced "scuzzy" ) bus technology that first appeared in the mid-1980s. SAS, like its predecessor, uses the standard SCSI command, SCSI command set. SAS offers optional compatibility with Serial ATA (SATA), versions 2 and later. This allows the connection of SATA drives to most SAS backplanes or controllers. The reverse, connecting SAS drives to SATA backplanes, is not possible. The T10 technical committee of the International Committee for Information Technology Standards (INCITS) develops and maintains the SAS protocol; the SCSI Trade Association (SCSITA) promotes the technology. Introduction A typical Serial Attached SCSI system consists of the following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hdparm
hdparm is a command line program for Linux to set and view ATA hard disk drive hardware parameters and test performance. It can set parameters such as drive caches, sleep mode, power management, acoustic management, and DMA settings. GParted GParted is a GTK front-end to GNU Parted and an official GNOME partition-editing application (alongside GNOME Disks, Disks). GParted is used for creating, deleting, resizing, moving, checking, and copying Partition (computing), disk partitions a ... and Parted Magic both include ''hdparm''. Changing hardware parameters from suboptimal conservative defaults to their optimal settings can improve performance greatly. For example, turning on DMA can, in some instances, double or triple data throughput. There is, however, no reliable method for determining the optimal settings for a given controller-drive combination, except careful trial and error. Depending on the given parameters, ''hdparm'' can cause computer crashes or render the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAID Controller
A disk array controller is a device that manages the physical disk drives Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are cons ... and presents them to the computer as logical units. It often implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache (computing), cache. ''Disk array controller'' is often ambiguously shortened to ''disk controller'' which can also refer to the circuitry responsible for managing internal disk drive operations. Front-end and back-end side A disk array controller provides front-end interfaces and back-end interfaces. * The back-end interface communicates with the controlled disks. Hence, its protocol is usually Advanced Technology Attachment, ATA (a.k.a. PATA), Serial ATA, SATA, SCSI, Fibre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process (power-on startup). The firmware comes pre-installed on the computer's motherboard. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS firmware was originally proprietary to the IBM PC; it was reverse engineered by some companies (such as Phoenix Technologies) looking to create compatible systems. The interface of that original system serves as a ''de facto'' standard. The BIOS in older PCs initializes and tests the system hardware components ( power-on self-test or POST for short), and loads a boot loader from a mass storage device which then initializes a kernel. In the era of DOS, the BIOS provided BIOS interrupt calls for the keyboard, display, st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Digital
Western Digital Corporation is an American data storage company headquartered in San Jose, California. Established in 1970, the company is one of the world's largest manufacturers of hard disk drives (HDDs). History 1970s Western Digital was founded on April 23, 1970, by Alvin B. Phillips, a Motorola employee, as General Digital Corporation, initially a manufacturer of MOS test equipment. It was originally based in Newport Beach, California, shortly thereafter moving to Santa Ana, California, and would go on to become one of the largest technology firms headquartered in Orange County. It rapidly became a specialty semiconductor maker, with start-up capital provided by several individual investors and industrial giant Emerson Electric. Around July 1971, it adopted its current name and soon introduced its first product, the ''WD1402A'' UART. During the early 1970s, the company focused on making and selling calculator chips, and by 1975, Western Digital was the largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power-up In Standby
In video games, a power-up is an object that adds temporary benefits or extra abilities to the player character as a game mechanic. This is in contrast to an item, which may or may not have a permanent benefit that can be used at any time chosen by the player. Although often collected directly through touch, power-ups can sometimes only be gained by collecting several related items, such as the floating letters of the word 'EXTEND' in ''Bubble Bobble''. Well known examples of power-ups that have entered popular culture include the power capsules from ''Pac-Man'' (regarded as the first power-up) and the Super Mushroom from ''Super Mario Bros.'', which ranked first in UGO Networks' ''Top 11 Video Game Powerups''. Items that confer power-ups are usually pre-placed in the game world, spawned randomly, dropped by beaten enemies or picked up from opened or smashed containers. They can be differentiated from items in other games, such as role-playing video games, by the fact that they t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-Monitoring, Analysis And Reporting Technology
Self-Monitoring, Analysis, and Reporting Technology (backronym S.M.A.R.T. or SMART) is a monitoring system included in computer hard disk drives (HDDs) and solid-state drives (SSDs). Its primary function is to detect and report various indicators of drive reliability, or how long a drive can function while anticipating imminent hardware failures. When S.M.A.R.T. data indicates a possible imminent drive failure, software running on the host system may notify the user so action can be taken to prevent data loss, and the failing drive can be replaced and no data is lost. Background Hard disk and other storage drives are subject to failures (see hard disk drive failure) which can be classified into two basic classes: * ''Predictable failures'' which result from slow processes such as mechanical wear and gradual degradation of storage surfaces. Monitoring can determine when such failures are becoming more likely. * ''Unpredictable failures'' which occur without warning due to anyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Disc Drive
In computing, an optical disc drive (ODD) is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, while other drives can both read and record. Those drives are called burners or writers since they physically burn the data onto the discs. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives. Although most laptop manufacturers no longer have optical drives bundled with their products, external drives are still available for purchase separately. Drive types Some drives can only read data where as others can both read data and write data to writable discs. Drives which can read but not write data are "-ROM" (read-only memory) drives, even if they can read from writable formats such as "-R" and "-RW". Some drives have mixed read and write capa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quiet PC
A quiet, silent or fanless PC is a personal computer that makes very little or no noise. Common uses for quiet PCs include video editing, sound mixing and home theater PCs, but noise reduction techniques can also be used to greatly reduce the noise from servers. There is currently no standard definition for a "quiet PC", and the term is generally not used in a business context, but by individuals and the businesses catering to them. A proposed general definition is that the sound emitted by such PCs should not exceed 30 dBA, but in addition to the average sound pressure level, the frequency spectrum and dynamics of the sound are important in determining if the sound of the computer is noticed. Sounds with a smooth frequency spectrum (lacking audible tonal peaks), and little temporal variation are less likely to be noticed. The character and amount of other noise in the environment also affects how much sound will be noticed or masked, so a computer may be quiet in relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
