Disk storage (also sometimes called drive storage ) is a data storage mechanism based on a rotating disk. The recording employs various electronic, magnetic, optical, or mechanical changes to the disk's surface layer. A disk drive is a device implementing such a storage mechanism. Notable types are hard disk drives (HDD), containing one or more non-removable rigid platters ; the floppy disk drive (FDD) and its removable floppy disk ; and various optical disc drives (ODD) and associated optical disc media.
31-707: NVS may refer to: Technology [ edit ] Non-volatile storage (NVS) or Non-volatile memory (NVM) is a type of computer memory NVS Telematic System Ltd is a Russian company that builds technology and equipment controlled by signals from satellite navigation systems NVSwitch is a successor of the Nvidia DGX-1 servers and workstations A line of business graphics cards from Nvidia, see Nvidia Quadro#For business NVS Education [ edit ] Institutionen for Neurobiologi, vardvetenskap och samhalle (NVS) (en. Dep of Neurobiology, Care Sciences and Society),
62-416: A magnetic tunnel junctions (MTJs), which works by controlling domain wall (DW) motion in ferromagnetic nanowires. Thinfilm produces rewriteable non-volatile organic ferroelectric memory based on ferroelectric polymers . Thinfilm successfully demonstrated roll-to-roll printed memories in 2009. In Thinfilm's organic memory the ferroelectric polymer is sandwiched between two sets of electrodes in
93-698: A department of Karolinska Institutet in Sweden Jawahar Navodaya Vidyalaya (JNVs), are schools in India that are run by Navodaya Vidyalaya Samiti (NVS) New Village School (NVS), a school in Sausalito, California, USA Other uses [ edit ] NVS and NOVN, the Swiss multinational pharmaceutical company Novartis is traded as NVS and NOVN See also [ edit ] NV (disambiguation) Topics referred to by
124-490: A few hundred to many thousands of bytes. Gross disk drive capacity is simply the number of disk surfaces times the number of blocks/surface times the number of bytes/block. In certain legacy IBM CKD drives the data was stored on magnetic disks with variable length blocks, called records; record length could vary on and between disks. Capacity decreased as record length decreased due to the necessary gaps between blocks. Digital disk drives are block storage devices . Each disk
155-747: A limited lifetime compared to volatile random access memory. Non-volatile data storage can be categorized into electrically addressed systems, for example, flash memory , and read-only memory ) and mechanically addressed systems ( hard disks , optical discs , magnetic tape , holographic memory , and such). Generally speaking, electrically addressed systems are expensive, and have limited capacity, but are fast, whereas mechanically addressed systems cost less per bit, but are slower. Electrically addressed semiconductor non-volatile memories can be categorized according to their write mechanism. Mask ROMs are factory programmable only and typically used for large-volume products which are not required to be updated after
186-451: A passive matrix. Each crossing of metal lines is a ferroelectric capacitor and defines a memory cell. Non-volatile main memory (NVMM) is primary storage with non-volatile attributes. This application of non-volatile memory presents security challenges. NVDIMM is one example of the non-volatile main memory. Disk storage (The spelling disk and disc are used interchangeably except where trademarks preclude one usage, e.g.,
217-660: A rotating magnetic disk to store data; access time is longer than for semiconductor memory, but the cost per stored data bit is very low, and they provide random access to any location on the disk. Formerly, removable disk packs were common, allowing storage capacity to be expanded. Optical discs store data by altering a pigment layer on a plastic disk and are similarly random access. Read-only and read-write versions are available; removable media again allows indefinite expansion, and some automated systems (e.g. optical jukebox ) were used to retrieve and mount disks under direct program control. Domain-wall memory (DWM) stores data in
248-423: A sequential read or write operation, after the drive accesses all the sectors in a track, it repositions the head(s) to the next track. This will cause a momentary delay in the flow of data between the device and the computer. In contrast, optical audio and video discs use a single spiral track that starts at the innermost point on the disc and flows continuously to the outer edge. When reading or writing data, there
279-431: A significant amount of time to erase data and write new data; they are not usually configured to be programmed by the processor of the target system. Data is stored using floating-gate transistors , which require special operating voltages to trap or release electric charge on an insulated control gate to store information. Flash memory is a solid-state chip that maintains stored data without any external power source. It
310-479: A simple dielectric layer the capacitor, an F-RAM cell contains a thin ferroelectric film of lead zirconate titanate [Pb(Zr,Ti)O 3 ] , commonly referred to as PZT. The Zr/Ti atoms in the PZT change polarity in an electric field, thereby producing a binary switch. Due to the PZT crystal maintaining polarity, F-RAM retains its data memory when power is shut off or interrupted. Due to this crystal structure and how it
341-473: A thin oxide layer, known as oxygen vacancies (oxide bond locations where the oxygen has been removed), which can subsequently charge and drift under an electric field. The motion of oxygen ions and vacancies in the oxide would be analogous to the motion of electrons and holes in a semiconductor. Although ReRAM was initially seen as a replacement technology for flash memory, the cost and performance benefits of ReRAM have not been enough for companies to proceed with
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#1732775741546372-534: Is a close relative to the EEPROM; it differs in that erase operations must be done on a block basis, and its capacity is substantially larger than that of an EEPROM. Flash memory devices use two different technologies—NOR and NAND—to map data. NOR flash provides high-speed random access, reading and writing data in specific memory locations; it can retrieve as little as a single byte. NAND flash reads and writes sequentially at high speed, handling data in blocks. However, it
403-422: Is developed mainly through two approaches: Thermal-assisted switching (TAS) which is being developed by Crocus Technology , and Spin-transfer torque (STT) which Crocus , Hynix , IBM , and several other companies are developing. Phase-change memory stores data in chalcogenide glass , which can reversibly change the phase between the amorphous and the crystalline state , accomplished by heating and cooling
434-1083: Is different from Wikidata All article disambiguation pages All disambiguation pages Non-volatile memory Non-volatile memory ( NVM ) or non-volatile storage is a type of computer memory that can retain stored information even after power is removed. In contrast, volatile memory needs constant power in order to retain data. Non-volatile memory typically refers to storage in memory chips , which store data in floating-gate memory cells consisting of floating-gate MOSFETs ( metal–oxide–semiconductor field-effect transistors ), including flash memory storage such as NAND flash and solid-state drives (SSD). Other examples of non-volatile memory include read-only memory (ROM), EPROM (erasable programmable ROM ) and EEPROM (electrically erasable programmable ROM), ferroelectric RAM , most types of computer data storage devices (e.g. disk storage , hard disk drives , optical discs , floppy disks , and magnetic tape ), and early computer storage methods such as punched tape and cards . Non-volatile memory
465-421: Is divided into logical blocks (collection of sectors). Blocks are addressed using their logical block addresses (LBA). Read from or write to disk happens at the granularity of blocks. Originally the disk capacity was quite low and has been improved in one of several ways. Improvements in mechanical design and manufacture allowed smaller and more precise heads, meaning that more tracks could be stored on each of
496-667: Is influenced, F-RAM offers distinct properties from other nonvolatile memory options, including extremely high, although not infinite, endurance (exceeding 10 read/write cycles for 3.3 V devices), ultra-low power consumption (since F-RAM does not require a charge pump like other non-volatile memories), single-cycle write speeds, and gamma radiation tolerance. Magnetoresistive RAM stores data in magnetic storage elements called magnetic tunnel junctions (MTJs). The first generation of MRAM, such as Everspin Technologies ' 4 Mbit, utilized field-induced writing. The second generation
527-455: Is sent from the computer processor to the BIOS into a chip controlling the data transfer. This is then sent out to the hard drive via a multi-wire connector. Once the data is received onto the circuit board of the drive, they are translated and compressed into a format that the individual drive can use to store onto the disk itself. The data is then passed to a chip on the circuit board that controls
558-419: Is slower on reading when compared to NOR. NAND flash reads faster than it writes, quickly transferring whole pages of data. Less expensive than NOR flash at high densities, NAND technology offers higher capacity for the same-size silicon. Ferroelectric RAM ( FeRAM , F-RAM or FRAM ) is a form of random-access memory similar in construction to DRAM , both use a capacitor and transistor but instead of using
589-517: Is typically used for the task of secondary storage or long-term persistent storage. The most widely used form of primary storage today is a volatile form of random access memory (RAM), meaning that when the computer is shut down, anything contained in RAM is lost. However, most forms of non-volatile memory have limitations that make them unsuitable for use as primary storage. Typically, non-volatile memory costs more, provides lower performance, or has
620-561: The Compact Disc logo. The choice of a particular form is frequently historical, as in IBM's usage of the disk form beginning in 1956 with the " IBM 350 disk storage unit ".) Audio information was originally recorded by analog methods (see Sound recording and reproduction ). Similarly the first video disc used an analog recording method. In the music industry, analog recording has been mostly replaced by digital optical technology where
651-456: The access to the drive. The drive is divided into sectors of data stored onto one of the sides of one of the internal disks. An HDD with two disks internally will typically store data on all four surfaces. The hardware on the drive tells the actuator arm where it is to go for the relevant track, and the compressed information is then sent down to the head, which changes the physical properties, optically or magnetically, for example, of each byte on
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#1732775741546682-557: The data is recorded in a digital format with optical information. The first commercial digital disk storage device was the IBM 350 which shipped in 1956 as a part of the IBM 305 RAMAC computing system. The random-access , low-density storage of disks was developed to complement the already used sequential-access , high-density storage provided by tape drives using magnetic tape . Vigorous innovation in disk storage technology, coupled with less vigorous innovation in tape storage, has reduced
713-425: The data on the device, mechanically addressed systems may be sequential access . For example, magnetic tape stores data as a sequence of bits on a long tape; transporting the tape past the recording head is required to access any part of the storage. Tape media can be removed from the drive and stored, giving indefinite capacity at the cost of the time required to retrieve a dismounted tape. Hard disk drives use
744-556: The device. An EPROM is an erasable ROM that can be changed more than once. However, writing new data to an EPROM requires a special programmer circuit. EPROMs have a quartz window that allows them to be erased with ultraviolet light, but the whole device is cleared at one time. A one-time programmable (OTP) device may be implemented using an EPROM chip without the quartz window; this is less costly to manufacture. An electrically erasable programmable read-only memory EEPROM uses voltage to erase memory. These erasable memory devices require
775-465: The difference in acquisition cost per terabyte between disk storage and tape storage; however, the total cost of ownership of data on disk including power and management remains larger than that of tape. Disk storage is now used in both computer storage and consumer electronic storage, e.g., audio CDs and video discs ( VCD , DVD and Blu-ray ). Data on modern disks is stored in fixed length blocks, usually called sectors and varying in length from
806-638: The disks. Advancements in data compression methods permitted more information to be stored in each of the individual sectors. The drive stores data onto cylinders, heads, and sectors . The sector unit is the smallest size of data to be stored in a hard disk drive, and each file will have many sector units assigned to it. The smallest entity in a CD is called a frame, which consists of 33 bytes and contains six complete 16-bit stereo samples (two bytes × two channels × six samples = 24 bytes). The other nine bytes consist of eight CIRC error-correction bytes and one subcode byte used for control and display. The information
837-632: The drive, thus storing the information. A file is not stored in a linear manner; rather, it is held in the best way for quickest retrieval. Mechanically there are two different motions occurring inside the drive. One is the rotation of the disks inside the device. The other is the side-to-side motion of the head across the disk as it moves between tracks. There are two types of disk rotation methods: Track positioning also follows two different methods across disk storage devices. Storage devices focused on holding computer data, e.g., HDDs, FDDs, and Iomega zip drives , use concentric tracks to store data. During
868-441: The glass. The crystalline state has low resistance, and the amorphous phase has high resistance, which allows currents to be switched ON and OFF to represent digital 1 and 0 states. FeFET memory uses a transistor with ferroelectric material to permanently retain state. RRAM (ReRAM) works by changing the resistance across a dielectric solid-state material often referred to as a memristor. ReRAM involves generating defects in
899-428: The memory device is manufactured. Programmable read-only memory (PROM) can be altered once after the memory device is manufactured using a PROM programmer . Programming is often done before the device is installed in its target system, typically an embedded system . The programming is permanent, and further changes require the replacement of the device. Data is stored by physically altering (burning) storage sites in
930-413: The replacement. Apparently, a broad range of materials can be used for ReRAM. However, the discovery that the popular high-κ gate dielectric HfO 2 can be used as a low-voltage ReRAM has encouraged researchers to investigate more possibilities. Mechanically addressed systems use a recording head to read and write on a designated storage medium. Since the access time depends on the physical location of
961-403: The same term [REDACTED] This disambiguation page lists articles associated with the title NVS . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=NVS&oldid=1066222317 " Category : Disambiguation pages Hidden categories: Short description