Computer data storage

2852:– A common solution to the problem is constantly maintaining an identical copy of device content on another device (typically of the same type). The downside is that this doubles the storage, and both devices (copies) need to be updated simultaneously with some overhead and possibly some delays. The upside is the possible concurrent reading of the same data group by two independent processes, which increases performance. When one of the replicated devices is detected to be defective, the other copy is still operational and is being utilized to generate a new copy on another device (usually available operational in a pool of stand-by devices for this purpose). 149: 912: 1706: 1037: 103: 390: 1675: 2889:

the probability of two failures in the same RAID group in time proximity is much smaller (approximately the probability squared, i.e., multiplied by itself). If a database cannot tolerate even such a smaller probability of data loss, then the RAID group itself is replicated (mirrored). In many cases such mirroring is done geographically remotely, in a different storage array, to handle recovery from disasters (see disaster recovery above).

777:) differs from primary storage in that it is not directly accessible by the CPU. The computer usually uses its input/output channels to access secondary storage and transfer the desired data to primary storage. Secondary storage is non-volatile (retaining data when its power is shut off). Modern computer systems typically have two orders of magnitude more secondary storage than primary storage because secondary storage is less expensive. 79: 122: 36: 345:) is typically corrected upon detection. A bit or a group of malfunctioning physical bits (the specific defective bit is not always known; group definition depends on the specific storage device) is typically automatically fenced out, taken out of use by the device, and replaced with another functioning equivalent group in the device, where the corrected bit values are restored (if possible). The 3252: 2948:(SAN) is a specialized network, that provides other computers with storage capacity. The crucial difference between NAS and SAN, is that NAS presents and manages file systems to client computers, while SAN provides access at block-addressing (raw) level, leaving it to attaching systems to manage data or file systems within the provided capacity. SAN is commonly associated with 2664:, has long been used to store information for automatic processing, particularly before general-purpose computers existed. Information was recorded by punching holes into the paper or cardboard medium and was read mechanically (or later optically) to determine whether a particular location on the medium was solid or contained a hole. 2003:. The information is accessed using one or more read/write heads which may contain one or more recording transducers. A read/write head only covers a part of the surface so that the head or medium or both must be moved relative to another in order to access data. In modern computers, magnetic storage will take these forms: 2770:. Holographic storage can utilize the whole volume of the storage medium, unlike optical disc storage, which is limited to a small number of surface layers. Holographic storage would be non-volatile, sequential-access, and either write-once or read/write storage. It might be used for secondary and off-line storage. See 1053:

Storage technologies at all levels of the storage hierarchy can be differentiated by evaluating certain core characteristics as well as measuring characteristics specific to a particular implementation. These core characteristics are volatility, mutability, accessibility, and addressability. For any

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Robotic-access storage devices may have a number of slots, each holding individual media, and usually one or more picking robots that traverse the slots and load media to built-in drives. The arrangement of the slots and picking devices affects performance. Important characteristics of such storage

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Device mirroring and typical RAID are designed to handle a single device failure in the RAID group of devices. However, if a second failure occurs before the RAID group is completely repaired from the first failure, then data can be lost. The probability of a single failure is typically small. Thus

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removable mass storage media into a storage device according to the system's demands; such data are often copied to secondary storage before use. It is primarily used for archiving rarely accessed information since it is much slower than secondary storage (e.g. 5–60 seconds vs. 1–10 milliseconds).

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is a medium for optical storage, generally consisting of a long and narrow strip of plastic, onto which patterns can be written and from which the patterns can be read back. It shares some technologies with cinema film stock and optical discs, but is compatible with neither. The motivation behind

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on HDDs reaches the proper placement and the data, subsequent data on the track are very fast to access. To reduce the seek time and rotational latency, data are transferred to and from disks in large contiguous blocks. Sequential or block access on disks is orders of magnitude faster than random

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is an intermediate stage between ultra-fast registers and much slower main memory. It was introduced solely to improve the performance of computers. Most actively used information in the main memory is just duplicated in the cache memory, which is faster, but of much lesser capacity. On the other

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In modern personal computers, most secondary and tertiary storage media are also used for off-line storage. Optical discs and flash memory devices are the most popular, and to a much lesser extent removable hard disk drives; older examples include floppy disks and Zip disks. In enterprise uses,

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methods allow in many cases (such as a database) to represent a string of bits by a shorter bit string ("compress") and reconstruct the original string ("decompress") when needed. This utilizes substantially less storage (tens of percent) for many types of data at the cost of more computation

1004:. The medium is recorded, usually in a secondary or tertiary storage device, and then physically removed or disconnected. It must be inserted or connected by a human operator before a computer can access it again. Unlike tertiary storage, it cannot be accessed without human interaction. 1023:

since it is physically inaccessible from a computer, and data confidentiality or integrity cannot be affected by computer-based attack techniques. Also, if the information stored for archival purposes is rarely accessed, off-line storage is less expensive than tertiary storage.

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access, and many sophisticated paradigms have been developed to design efficient algorithms based on sequential and block access. Another way to reduce the I/O bottleneck is to use multiple disks in parallel to increase the bandwidth between primary and secondary memory.

186:, which puts fast but expensive and small storage options close to the CPU and slower but less expensive and larger options further away. Generally, the fast technologies are referred to as "memory", while slower persistent technologies are referred to as "storage". 2810:. It was first done in 2012, when researchers achieved a ratio of 1.28 petabytes per gram of DNA. In March 2017 scientists reported that a new algorithm called a DNA fountain achieved 85% of the theoretical limit, at 215 petabytes per gram of DNA. 715:

run programs directly from ROM (or similar), because such programs are rarely changed. Standard computers do not store non-rudimentary programs in ROM, and rather, use large capacities of secondary storage, which is non-volatile as well, and not as costly.

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The accessing of pieces of information will be in a serial order, one after the other; therefore the time to access a particular piece of information depends upon which piece of information was last accessed. Such characteristic is typical of off-line

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of the material. Phase-change memory would be non-volatile, random-access read/write storage, and might be used for primary, secondary and off-line storage. Most rewritable and many write-once optical disks already use phase-change material to store

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As of 2011, the most commonly used data storage media are semiconductor, magnetic, and optical, while paper still sees some limited usage. Some other fundamental storage technologies, such as all-flash arrays (AFAs) are proposed for development.

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requires constant power to maintain the stored information. The fastest memory technologies are volatile ones, although that is not a universal rule. Since the primary storage is required to be very fast, it predominantly uses volatile memory.

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While a group of bits malfunction may be resolved by error detection and correction mechanisms (see above), storage device malfunction requires different solutions. The following solutions are commonly used and valid for most storage devices:

360:(compress and decompress when needed). Analysis of the trade-off between storage cost saving and costs of related computations and possible delays in data availability is done before deciding whether to keep certain data compressed or not. 225:

Without a significant amount of memory, a computer would merely be able to perform fixed operations and immediately output the result. It would have to be reconfigured to change its behavior. This is acceptable for devices such as desk

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Allows information to be overwritten at any time. A computer without some amount of read/write storage for primary storage purposes would be useless for many tasks. Modern computers typically use read/write storage also for secondary

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Magnetic storage does not have a definite limit of rewriting cycles like flash storage and re-writeable optical media, as altering magnetic fields causes no physical wear. Rather, their life span is limited by mechanical parts.

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has steadily gained share as off-line storage for home computers. Non-volatile semiconductor memory is also used for secondary storage in various advanced electronic devices and specialized computers that are designed for them.

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since the detached medium can easily be physically transported. Additionally, it is useful for cases of disaster, where, for example, a fire destroys the original data, a medium in a remote location will be unaffected, enabling

201:'s Analytical Machine, clearly distinguished between processing and memory (Babbage stored numbers as rotations of gears, while Ludgate stored numbers as displacements of rods in shuttles). This distinction was extended in the 336:

bit value flipping, or "physical bit fatigue", loss of the physical bit in the storage of its ability to maintain a distinguishable value (0 or 1), or due to errors in inter or intra-computer communication. A random

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As the RAM types used for primary storage are volatile (uninitialized at start up), a computer containing only such storage would not have a source to read instructions from, in order to start the computer. Hence,

4210: 551:, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. Any data actively operated on is also stored there in a uniform manner. 2788:

that can store electric charge. Molecular memory might be especially suited for primary storage. The theoretical storage capacity of molecular memory is 10 terabits per square inch (16 Gbit/mm).

1469:. In modern computers, location-addressable storage usually limits to primary storage, accessed internally by computer programs, since location-addressability is very efficient, but burdensome for humans. 332:

By adding bits to each encoded unit, redundancy allows the computer to detect errors in coded data and correct them based on mathematical algorithms. Errors generally occur in low probabilities due to

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for tertiary storage. It may make sense to separate read latency and write latency (especially for non-volatile memory) and in case of sequential access storage, minimum, maximum and average latency.

1350:(UPS) can be used to give a computer a brief window of time to move information from primary volatile storage into non-volatile storage before the batteries are exhausted. Some systems, for example 3256: 4015: 1595:

may also be used. As with latency, read rate and write rate may need to be differentiated. Also accessing media sequentially, as opposed to randomly, typically yields maximum throughput.

2433:. The deformities may be permanent (read only media), formed once (write once media) or reversible (recordable or read/write media). The following forms are in common use as of 2009: 2864:) – This method generalizes the device mirroring above by allowing one device in a group of devices to fail and be replaced with the content restored (Device mirroring is RAID with 1343:

is a form of volatile memory similar to DRAM with the exception that it never needs to be refreshed as long as power is applied; it loses its content when the power supply is lost.

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The rate at which information can be read from or written to the storage. In computer data storage, throughput is usually expressed in terms of megabytes per second (MB/s), though

878:) to a swap file or page file on secondary storage, retrieving them later when needed. If a lot of pages are moved to slower secondary storage, the system performance is degraded. 601:

to improve both reading and writing performance. Operating systems borrow RAM capacity for caching so long as it's not needed by running software. Spare memory can be utilized as

874:, allowing the utilization of more primary storage capacity than is physically available in the system. As the primary memory fills up, the system moves the least-used chunks ( 2961:

Large quantities of individual magnetic tapes, and optical or magneto-optical discs may be stored in robotic tertiary storage devices. In tape storage field they are known as

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Hardware memory encryption is available in Intel Architecture, supporting Total Memory Encryption (TME) and page granular memory encryption with multiple keys (MKTME). and in

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Any location in storage can be accessed at any moment in approximately the same amount of time. Such characteristic is well suited for primary and secondary storage. Most

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to fetch the medium and place it in a drive. When the computer has finished reading the information, the robotic arm will return the medium to its place in the library.

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Read/write storage which allows information to be overwritten multiple times, but with the write operation being much slower than the read operation. Examples include

1746:, of which high counts signify deteriorating and/or low-quality media. Too many consecutive minor errors can lead to data corruption. Not all vendors and models of 3978: 981:

For example, always-on spinning hard disk drives are online storage, while spinning drives that spin down automatically, such as in massive arrays of idle disks (

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to store information. These primary storage devices were short-lived in the market, since the Williams tube was unreliable, and the Selectron tube was expensive.

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The compactness of stored information. It is the storage capacity of a medium divided with a unit of length, area or volume (e.g. 1.2 megabytes per square inch).

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have no moving parts and consume less power than hard disks. Also, memory may use more power than hard disks. Large caches, which are used to avoid hitting the

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to perform various calculations or other operations on this data (or with the help of it). Registers are the fastest of all forms of computer data storage.

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Most contemporary computers use volatile technologies (which lose data when power is off); early computers used both volatile and persistent technologies.

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Storage devices that reduce fan usage automatically shut-down during inactivity, and low power hard drives can reduce energy consumption by 90 percent.

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Light induced magnetization melting in magnetic photoconductors has also been proposed for high-speed low-energy consumption magneto-optical storage.

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surface stores information. The information is read optically and written by combining magnetic and optical methods. Magneto-optical disc storage is

919:, with tape cartridges placed on shelves in the front, and a robotic arm moving in the back. The visible height of the library is about 180 cm. 1876: 2108: 242:

and data. Such computers are more versatile in that they do not need to have their hardware reconfigured for each new program, but can simply be

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are possible expansion options: adding slots, modules, drives, robots. Tape libraries may have from 10 to more than 100,000 slots, and provide

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is from the CPU. This traditional division of storage to primary, secondary, tertiary, and off-line storage is also guided by cost per bit.

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1515:(computer device), with hardware being faster but more expensive option. Hardware content addressable memory is often used in a computer's 3750: 1324:

retains the stored information even if not constantly supplied with electric power. It is suitable for long-term storage of information.

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The size of the largest "chunk" of data that can be efficiently accessed as a single unit, e.g. without introducing additional latency.

4138: 278:, equal to 8 bits. A piece of information can be handled by any computer or device whose storage space is large enough to accommodate 2969:, or optical disk libraries per analogy. The smallest forms of either technology containing just one drive device are referred to as 3578: 2722:

to store information. Delay-line memory was dynamic volatile, cycle sequential read/write storage, and was used for primary storage.

2425:, stores information in deformities on the surface of a circular disc and reads this information by illuminating the surface with a 711:, as updates to them are possible; however it is slow and memory must be erased in large portions before it can be re-written. Some 4410: 3605: 2884:, at the cost of more processing during both regular operation (with often reduced performance) and defective device replacement. 4240: 3804: 3632: 3443: 1847:(SSDs) as default configuration options for the secondary storage either in addition to or instead of the more traditional HDD. 589:(RAM). It is small-sized, light, but quite expensive at the same time. The particular types of RAM used for primary storage are 3926: 2552: 3394: 3261: 670:(MMU) is a small device between CPU and RAM recalculating the actual memory address, for example to provide an abstraction of 608:

As shown in the diagram, traditionally there are two more sub-layers of the primary storage, besides main large-capacity RAM:

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developing this technology was the possibility of far greater storage capacities than either magnetic tape or optical discs.

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This is primarily useful for extraordinarily large data stores, accessed without human operators. Typical examples include

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to make the operation more understandable. In modern computers, secondary, tertiary and off-line storage use file systems.

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between successive computations to build up complex procedural results. Most modern computers are von Neumann machines.

2901:. This concept does not pertain to the primary storage, which is shared between multiple processors to a lesser degree. 2668:

make it possible for objects that are sold or transported to have some computer-readable information securely attached.

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Each individually accessible unit of information is selected based on the basis of (part of) the contents stored there.

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with new in-memory instructions; they also tend to be simpler to design, in that a relatively simple processor may keep

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particular implementation of any storage technology, the characteristics worth measuring are capacity and performance.

2173: 1390:(WORM) allows the information to be written only once at some point after manufacture. Examples include semiconductor 3685:"Power consumption – Tom's hardware : Conventional hard drive obsoletism? Samsung's 32 GB flash drive previewed" 3684: 3314: 2545: 1785: 4262: 1694: 1335:

is a form of volatile memory that also requires the stored information to be periodically reread and rewritten, or

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in storage to prevent the possibility of unauthorized information reconstruction from chunks of storage snapshots.

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The total amount of stored information that a storage device or medium can hold. It is expressed as a quantity of

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Relatively small amounts of digital data (compared to other digital data storage) may be backed up on paper as a

1862: 213:(ALU). The former controls the flow of data between the CPU and memory, while the latter performs arithmetic and 182:(CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a 3830: 2908:(DAS) is a traditional mass storage, that does not use any network. This is still a most popular approach. This 982: 630:

hand, main memory is much slower, but has a much greater storage capacity than processor registers. Multi-level

5230: 5225: 5098: 3523: 2094: 1492: 5128: 4938: 3372: 1391: 555: 287: 270:. Text, numbers, pictures, audio, and nearly any other form of information can be converted into a string of 1028:

magnetic tape cartridges are predominant; older examples include open-reel magnetic tape and punched cards.

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long-unused files from fast hard disk storage to libraries or jukeboxes. If the files are needed, they are

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storage to RAM and start to execute it. A non-volatile technology used for this purpose is called ROM, for

616: 274:, or binary digits, each of which has a value of 0 or 1. The most common unit of storage is the 5027: 4603: 4545: 3365:"Primary storage or storage hardware (shows usage of term "primary storage" meaning "hard disk storage")" 3080: 2452:: Read only storage, used for mass distribution of digital information (music, video, computer programs); 1683: 1504: 1340: 985:), are nearline storage. Removable media such as tape cartridges that can be automatically loaded, as in 974:

Nearline storage is not immediately available, but can be made online quickly without human intervention.

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because it is "near to online". The formal distinction between online, nearline, and offline storage is:

800:(billionths of a second). Thus, secondary storage is significantly slower than primary storage. Rotating 593:, meaning that they lose the information when not powered. Besides storing opened programs, it serves as 3564: 863:

describing the owner of a certain file, the access time, the access permissions, and other information.

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Flash storage may experience downspiking transfer rates as a result of accumulating errors, which the

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to store information in an X–Y addressable matrix and reads the information by observing the varying

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When a computer needs to read information from the tertiary storage, it will first consult a catalog

398: 231: 3350: 2918:(NAS) is mass storage attached to a computer which another computer can access at file level over a 2675:

for very long-term storage, as the longevity of paper typically exceeds even magnetic data storage.

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Offline storage is not immediately available, and requires some human intervention to become online.

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In modern computers, primary storage almost exclusively consists of dynamic volatile semiconductor

1656: 247: 235: 202: 1743: 1709: 1235: 4856: 4851: 4739: 4712: 4367: 4179: 3904: 3718: 3460: 3432:. Series on foundations and trends in theoretical computer science. Hanover, MA: now Publishers. 2905: 2524: 2499: 2153: 2147: 2141: 2135: 1789: 1732: 1188: 1001: 663: 394: 346: 179: 989:, are nearline storage, while tape cartridges that must be manually loaded are offline storage. 812:

drives, have even longer access times. Other examples of secondary storage technologies include

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of near-line information. Optical jukeboxes are somewhat smaller solutions, up to 1,000 slots.

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to determine which tape or disc contains the information. Next, the computer will instruct a

856: 796:(thousandths of a second), while the access time per byte for primary storage is measured in 620: 422: 418: 302: 267: 210: 3874: 1808:

forms of semiconductor memory exist, the former using standard MOSFETs and the latter using

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Each individually accessible unit of information in storage is selected with its numerical

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is a level below secondary storage. Typically, it involves a robotic mechanism which will

8: 5164: 5083: 4608: 3586: 3176: 2935: 2927: 2738: 2405: 1568: 1321: 679: 129: 45: 4305: 4172:"New method of self-assembling nanoscale elements could transform data storage industry" 4153: 4098: 4325: 4115: 4084: 4072: 3108: 3103: 2970: 2919: 2653: 2568: 1792:. A semiconductor memory chip may contain millions of memory cells, consisting of tiny 1781: 1747: 1682:

Distinct types of data storage have different points of failure and various methods of

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directory and file names. The underlying device is still location-addressable, but the

1011: 886: 801: 687: 662:, that indicates the desired location of data. Then it reads or writes the data in the 612: 575: 314: 3601: 5149: 5059: 4756: 4620: 4518: 4430: 4317: 4232: 4120: 3930: 3808: 3628: 3433: 3424: 3400: 3320: 3310: 3171: 3134: 3065: 3048: 2923: 2719: 2715: 2711: 2628: 2326: 2164: 1844: 1636: 1607:

The probability of spontaneous bit value change under various conditions, or overall

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Main memory is directly or indirectly connected to the central processing unit via a

559: 452: 214: 194: 183: 50: 4329: 3979:"MacBook Air replaces the standard notebook hard disk for solid state flash storage" 1000:

is computer data storage on a medium or a device that is not under the control of a

5133: 4591: 4482: 4376: 4309: 4110: 4102: 3271: 3196: 3113: 2898: 2779: 2692: 2057: 2053: 1988: 1975: 1939: 1885: 1840: 1488: 1086: 963: 955: 902: 867: 755: 739: 695: 631: 456: 384: 356: 283: 4032: 3533: 1635:

2.5-inch hard disk drives often consume less power than larger ones. Low capacity

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provide random access, though both semiconductor and flash memories have minimal

1436: 1325: 1066: 944: 882: 813: 781: 712: 698:(the terminology may be somewhat confusing as most ROM types are also capable of 626: 590: 527: 460: 350: 306: 190: 3529:

Federal Standard 1037C – Telecommunications: Glossary of Telecommunication Terms

1354:, have integrated batteries that maintain volatile storage for several minutes. 5200: 5064: 4816: 4717: 4487: 4470: 4381: 4362: 4203:"This speck of DNA contains a movie, a computer virus, and an Amazon gift card" 3956: 3161: 3075: 3058: 2974: 2962: 2847: 2825: 2696: 2672: 2193: 2061: 1951: 1897: 1725: 1705: 1484: 1466: 1336: 986: 940: 871: 671: 659: 1036: 570:

as primary storage. By 1954, those unreliable methods were mostly replaced by

102: 5219: 5185: 5069: 4918: 4908: 4888: 4704: 4630: 4583: 4528: 4523: 4475: 3532:(Technical report). General Services Administration. FS-1037C. Archived from 3093: 2949: 2688: 2510: 1992: 1963: 1903: 1824: 1797: 1777: 1739: 1479: 1422: 1351: 906: 852: 700: 563: 410: 364: 198: 4395: 4313: 4054: 3662: 3324: 2996:, and for high-capacity archives in imaging, medical, and video industries. 2796:

store magnetic information, which can be modified by low-light illumination.

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and is slow write, fast read storage used for tertiary and off-line storage.

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Retains the information stored at the time of manufacture. Examples include

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The time it takes to access a particular location in storage. The relevant

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when compared to hard disk drives, as no mechanical parts need to be moved.

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consists of storage devices and their media not directly accessible by the

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hard disk drive (HDD) from 1999. When connected to a computer it serves as

110: 72: 4033:"Comparing SSD and HDD - A comprehensive comparison of the storage drives" 3848: 3731: 1294:

Mid-term archival, routine backups, server, workstation storage expansion

5190: 4893: 4861: 4764: 4724: 4687: 4655: 4497: 4073:"Optically switched magnetism in photovoltaic perovskite CH3NH3(Mn:Pb)I3" 3124: 3053: 3033: 2700: 2426: 2049: 2045: 2013: 1957: 1909: 1854: 1640: 1576: 1472: 848: 817: 793: 789: 658:. The CPU firstly sends a number through an address bus, a number called 651: 567: 389: 368: 4106: 2521:, slow write, fast read storage used for tertiary and off-line storage. 2492:: Slow write, fast read storage, used for tertiary and off-line storage; 2086: 506:. Meanwhile, slower persistent storage devices have been referred to as 4625: 4555: 4550: 4540: 3186: 3146: 2807: 2657: 2610: 1690: 1620: 1572: 1207: 1044: 851:

format, which provides the abstraction necessary to organize data into

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Various forms of storage, divided according to their distance from the

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machines differ in having a memory in which they store their operating

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A secondary or tertiary storage may connect to a computer utilizing

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Generally, the lower a storage is in the hierarchy, the lesser its

291: 259: 164: 126: 107: 91: 83: 78: 4290:"DNA Fountain enables a robust and efficient storage architecture" 3351:"Documentation for /proc/sys/vm/ — The Linux Kernel documentation" 3087: 1678:

S.M.A.R.T. software warning suggests impending hard drive failure.

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in some uses refer to what was historically called, respectively,

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the computer, that is, to read a larger program from non-volatile

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of data (often 32 or 64 bits). CPU instructions instruct the

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are located inside the processor. Each register typically holds a

574:. Core memory remained dominant until the 1970s, when advances in 121: 4675: 4613: 4567: 3297:

Computer organization and design: The hardware/software interface

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Karen Scarfone; Murugiah Souppaya; Matt Sexton (November 2007).

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is estimable using S.M.A.R.T. diagnostic data that includes the

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volume and virtual disk encryption, andor file/folder encryption

175:. It is a core function and fundamental component of computers. 5113: 5108: 4789: 4562: 3734:"Guide to storage encryption technologies for end user devices" 2993: 2477: 2463: 2449: 2441: 2338: 2308: 2302: 2211: 2199: 1836: 1793: 1728:

and the count of spin-ups, though its reliability is disputed.

1713: 1616: 1580: 1409: 743: 397:. The fundamental components of a general-purpose computer are 333: 326: 4989: 3522: 1823:(DRAM). Since the turn of the century, a type of non-volatile 1784:(IC) chips to store information. Data are typically stored in 1716:. The minor errors are correctable and within a healthy range. 290:, about 1250 pages in print, can be stored in about five 5169: 5118: 5043: 4051:"The DVD FAQ - A comprehensive reference of DVD technologies" 3579:"How much of the [re]drive is actually eco-friendly?" 2593: 2489: 2473: 2470:: Write once storage, used for tertiary and off-line storage; 2459: 2376: 2255: 1663: 1374: 1099: 318: 87: 4139:"A paper-based backup solution (not as stupid as it sounds)" 4866: 4760: 3805:"Introduction to SPARC M7 and silicon secured memory (SSM)" 2860: 2829: 2467: 2455: 2249: 2243: 1537: 1483:

of variable length, and a particular file is selected with

1395: 683: 440: 322: 275: 263: 1689:

Vulnerabilities that can instantly lead to total loss are

638:

being smallest, fastest and located inside the processor;

4846: 4670: 2445: 2184: 1999:

coated surface to store information. Magnetic storage is

1533: 1378: 1047: 809: 448: 271: 4009:"Comparing SSD and HDD endurance in the age of QLC SSDs" 3396:

The Essentials of Computer Organization and Architecture

2074:

Magnetic tape was then often used for secondary storage.

4360: 2437: 2040:

In early computers, magnetic storage was also used as:

805: 253: 3953:"MacBook Air – The best of iPad meets the best of Mac" 2509:

is optical disc storage where the magnetic state on a

2429:

and observing the reflection. Optical disc storage is

4263:"DNA could store all of the world's data in one room" 3927:"Mac Pro – Storage and RAID options for your Mac Pro" 3897:"Toshiba tosses hat into notebook flash storage ring" 3867:"New Samsung notebook replaces hard drive with flash" 280:

the binary representation of the piece of information

3000:

is a most known archiving strategy of automatically

2678: 2071:) or off line storage in the form of magnetic cards; 847:

Secondary storage is often formatted according to a

650:. It is actually two buses (not on the diagram): an 294:(40 million bits) with one byte per character. 3831:"What S.M.A.R.T. hard disk errors actually tell us" 792:per byte for HDDs or SSDs is typically measured in 152:

Read/Write DVD drive with cradle for media extended

3426:Algorithms and data structures for external memory 3294: 788:(SSDs) are usually used as secondary storage. The 3739:. National Institute of Standards and Technology. 3292: 5217: 1669: 1623:can be used to measure IO performance in Linux. 971:Online storage is immediately available for I/O. 313:object. Many standards exist for encoding (e.g. 205:, where the CPU consists of two main parts: The 4288:Erlich, Yaniv; Zielinski, Dina (2 March 2017). 4287: 4066: 4064: 3293:Patterson, David A.; Hennessy, John L. (2005). 3088:Secondary, tertiary and off-line storage topics 2912:was coined recently, together with NAS and SAN. 1659:is readily available for most storage devices. 1240:Indicated by downward spikes in transfer rates 3708: 3706: 467:drives, and other devices slower than RAM but 409:devices. Technology and capacity as in common 4975: 4944:History of computing hardware (1960s–present) 4425: 4411: 3715:"SSD, i-RAM and traditional hard disk drives" 3712: 3157:Noise-predictive maximum-likelihood detection 2553: 2102: 1870: 1031: 27:Storage of digital data readable by computers 4061: 3419: 2567: 3783:"A proposed API for full-memory encryption" 3703: 3288: 3286: 3284: 3207: 1643:, may also consume a large amount of power. 4982: 4968: 4418: 4404: 3661:. 12 July 2006. p. 13. Archived from 3655:"Super Talent's 2.5" IDE flash hard drive" 3602:"IS the Silent PC Future 2.5-inches wide?" 3498:IBM developer-works, inside system storage 3485: 2560: 2546: 2109: 2095: 1884: 1877: 1863: 478:has, depending on technology, been called 4380: 4114: 4088: 3626: 3599: 3016: 2116: 2030:, used for tertiary and off-line storage; 4151: 3281: 1843:manufacturers started using flash-based 1704: 1673: 1035: 910: 471:(retaining contents when powered down). 388: 147: 120: 101: 77: 71:For broader coverage of this topic, see 4070: 3491: 3399:. Jones & Bartlett Learning. 2006. 2892: 2814: 1491:of a computer provides the file system 1304:Portable electronics; operating system 605:for temporary high-speed data storage. 378: 14: 5218: 3473:from the original on 27 September 2007 2934:. NAS is commonly associated with the 707:Many types of "ROM" are not literally 4963: 4399: 3929:. Apple. 27 July 2006. Archived from 3635:from the original on 5 September 2008 2541: 2090: 1858: 1363:Read/write storage or mutable storage 1019:. Off-line storage increases general 443:(dynamic RAM) or other such devices. 4990: 4949:List of pioneers in computer science 4071:Náfrádi, Bálint (24 November 2016). 4021:from the original on 9 October 2022. 3807:. swisdev.oracle.com. Archived from 3449:from the original on 4 January 2011. 2856:Redundant array of independent disks 2762:stores information optically inside 2743:uses different mechanical phases of 761: 682:containing a small startup program ( 666:using the data bus. Additionally, a 582:to become economically competitive. 353:. A detected error is then retried. 254:Data organization and representation 136:storage. When used within a robotic 29: 3763:from the original on 9 October 2022 992: 896: 301:by assigning a bit pattern to each 24: 4361:Goda, K.; Kitsuregawa, M. (2012). 4354: 4265:. Science Magazine. 2 March 2017. 4152:Sterling, Bruce (16 August 2012). 3985:. 15 November 2010. Archived from 3494:"Correct use of the term nearline" 2956: 2880:saves storage, when compared with 1744:measuring correctable minor errors 1700: 1666:M7 generation since October 2015. 1174:Lack of random access (very slow) 961:Tertiary storage is also known as 521: 25: 5242: 4269:from the original on 2 March 2017 4243:from the original on 2 March 2017 4213:from the original on 3 March 2017 3608:from the original on 20 July 2008 2679:Other storage media or substrates 2498:or UDO is similar in capacity to 1456: 893:, are usually block-addressable. 881:The secondary storage, including 642:being somewhat larger and slower. 234:, and other specialized devices. 189:Even the first computer designs, 4363:"The history of storage systems" 4344:"Disaster Recovery on AWS Cloud" 4200: 3255: This article incorporates 3250: 3116:used for capturing research data 1762: 1753: 1695:failure of electronic components 1416: 1286:Moderate (but expensive drives) 1266:Very low (but expensive drives) 220: 34: 4336: 4281: 4255: 4225: 4194: 4164: 4145: 4131: 4043: 4025: 4001: 3971: 3945: 3919: 3889: 3859: 3841: 3823: 3797: 3775: 3743: 3725: 3713:Aleksey Meyev (23 April 2008). 3677: 3647: 3627:Mike Chin (18 September 2002). 3620: 3593: 3571: 3553: 3516: 3268:General Services Administration 2998:Hierarchical storage management 2965:, and in optical storage field 738:The primary storage, including 547:), often referred to simply as 4178:. 1 March 2009. Archived from 3524:National Communications System 3461:"A thesis on tertiary storage" 3453: 3413: 3387: 3357: 3343: 3331: 3231: 1827:semiconductor memory known as 1693:on mechanical hard drives and 1556: 432:is usually fast but temporary 367:, certain types of data (e.g. 163:is a technology consisting of 132:tape cartridge, an example of 13: 1: 4991:Primary computer data storage 4939:History of computing hardware 3873:. 23 May 2006. Archived from 3849:"QPxTool - check the quality" 3244: 2819: 2044:Primary storage in a form of 2022:, used for secondary storage. 1670:Vulnerability and reliability 1626: 1392:programmable read-only memory 1370:Slow write, fast read storage 1357: 1339:, otherwise it would vanish. 1316: 288:complete works of Shakespeare 4807:Network interface controller 3717:. X-bit labs. Archived from 3369:searchstorage.techtarget.com 3044:Memory cell (disambiguation) 3028:Dynamic random-access memory 2992:Robotic storage is used for 2507:Magneto-optical disc storage 2016:, used for off-line storage; 1821:dynamic random-access memory 1794:MOS field-effect transistors 1477:Information is divided into 1348:uninterruptible power supply 1333:Dynamic random-access memory 680:non-volatile primary storage 634:setup is also commonly used— 516:auxiliary/peripheral storage 7: 4604:Refreshable braille display 4546:Refreshable braille display 3561:"Energy savings calculator" 3081:Static random-access memory 3011: 2656:, typically in the form of 1991:uses different patterns of 1850: 1684:predictive failure analysis 1647: 1579:for secondary storage, and 1523: 1505:Content-addressable storage 1341:Static random-access memory 421:and the greater its access 325:, and video encodings like 43:It has been suggested that 10: 5247: 4382:10.1109/JPROC.2012.2189787 3600:Mike Chin (8 March 2004). 3307:Morgan Kaufmann Publishers 3023:Aperture (computer memory) 2833: 2823: 2806:stores information in DNA 2772:Holographic Versatile Disc 2082: 1766: 1032:Characteristics of storage 900: 525: 382: 70: 60:Proposed since April 2024. 5178: 5142: 5091: 5082: 5052: 5036: 5007: 4998: 4931: 4875: 4834: 4825: 4703: 4639: 4582: 4511: 4446: 4437: 4392:, Computer history museum 3629:"Recommended hard drives" 2603: 2576: 2386: 2350:Magneto-optic Kerr effect 2348: 2265: 2233: 2183: 2163: 2125: 1893: 1786:metal–oxide–semiconductor 1507:can be implemented using 1214: 1104: 399:arithmetic and logic unit 371:information) may be kept 232:digital signal processors 4154:"PaperBack paper backup" 3224: 3219:Storage World Conference 3214:Storage Networking World 3208:Data storage conferences 2916:Network-attached storage 2793:Magnetic photoconductors 2758:Holographic data storage 2635:Optical mark recognition 2533: 2527:has also been proposed. 1750:support error scanning. 203:Von Neumann architecture 171:that are used to retain 4713:Central processing unit 4368:Proceedings of the IEEE 4314:10.1126/science.aaj2038 3955:. Apple. Archived from 2906:Direct-attached storage 2718:in a substance such as 2708:Electro-acoustic memory 2525:3D optical data storage 1733:flash memory controller 1040:A 1 GiB module of 859:, while also providing 428:In contemporary usage, 395:central processing unit 347:cyclic redundancy check 321:, image encodings like 180:central processing unit 3853:qpxtool.sourceforge.io 3756:. software.intel.com. 3548:Federal standard 1037C 3492:Pearson, Tony (2010). 3263:Federal Standard 1037C 3257:public domain material 3162:Object(-based) storage 3152:Information repository 3017:Primary storage topics 2784:stores information in 1717: 1710:Error rate measurement 1679: 1548:Memory storage density 1511:(computer program) or 1429:semiconductor memories 1236:Error rate measurement 1201:Failure with imminent 1050: 920: 668:memory management unit 414: 153: 145: 140:, it is classified as 118: 99: 5231:Computer architecture 5226:Computer data storage 4077:Nature Communications 4037:www.stellarinfo.co.in 4014:. Micron technology. 3071:Page address register 2749:electrical resistance 2745:phase-change material 2496:Ultra Density Optical 1810:floating-gate MOSFETs 1742:can be determined by 1735:attempts to correct. 1720:Impending failure on 1708: 1677: 1575:for primary storage, 1243:(Short-term storage) 1039: 914: 780:In modern computers, 621:arithmetic logic unit 405:, storage space, and 392: 268:binary numeral system 211:arithmetic logic unit 157:Computer data storage 151: 124: 105: 81: 5196:Magnetic-core memory 4390:Memory & storage 3721:on 18 December 2008. 3567:on 21 December 2008. 3375:on 10 September 2008 3182:Virtual tape library 3130:List of file formats 3099:Hybrid cloud storage 2946:Storage area network 2926:, or in the case of 2893:Network connectivity 2815:Related technologies 1819:(RAM), particularly 1817:random-access memory 1774:Semiconductor memory 1769:Semiconductor memory 1653:Full disk encryption 1462:Location-addressable 1388:Write once read many 1297:Long-term archival, 1082:Random-access memory 1021:information security 1012:transfer information 841:disk read/write head 587:random-access memory 580:semiconductor memory 572:magnetic-core memory 379:Hierarchy of storage 341:(e.g. due to random 161:digital data storage 53:into this article. ( 5084:Non-volatile memory 4306:2017Sci...355..950E 4107:10.1038/ncomms13406 4099:2016NatCo...713406N 3983:news.inventhelp.com 3877:on 30 December 2010 3691:. 20 September 2006 3504:on 24 November 2015 3274:on 22 January 2022. 2928:online file storage 2836:Storage replication 2739:Phase-change memory 1569:unit of measurement 1499:Content-addressable 1322:Non-volatile memory 1310:Long-term archival 1165:~150 ms (moderate) 1059: 1010:storage is used to 870:use the concept of 613:Processor registers 585:This led to modern 578:technology allowed 315:character encodings 286:. For example, the 46:Non-volatile memory 4057:on 22 August 2009. 3811:on 21 January 2019 3751:"Encryption specs" 3665:on 26 January 2012 3109:Data proliferation 3104:Data deduplication 2920:local area network 2868:). RAID groups of 2684:Vacuum-tube memory 2654:Paper data storage 2569:Paper data storage 1845:solid-state drives 1835:As early as 2006, 1782:integrated circuit 1726:hours of operation 1718: 1697:on flash storage. 1680: 1637:solid-state drives 1615:Utilities such as 1384:Write once storage 1057: 1051: 921: 786:solid-state drives 632:hierarchical cache 576:integrated circuit 415: 215:logical operations 154: 146: 119: 100: 5213: 5212: 5209: 5208: 5078: 5077: 5060:Delay-line memory 4957: 4956: 4927: 4926: 4857:Analog audio jack 4578: 4577: 4346:. 18 August 2023. 4300:(6328): 950–954. 4141:. 14 August 2012. 3989:on 23 August 2011 3901:technewsworld.com 3837:. 6 October 2016. 3589:on 5 August 2008. 3546:See also article 3526:(7 August 1996). 3439:978-1-60198-106-6 3406:978-0-7637-3769-6 3172:Solid-state drive 3135:Global filesystem 3066:Memory protection 3049:Memory management 2967:optical jukeboxes 2924:wide area network 2899:computer networks 2712:Delay-line memory 2650: 2649: 2629:Edge-notched card 2519:sequential access 2415: 2414: 2165:Professional Disc 2036:(magnetic rolls). 1985: 1984: 1796:(MOSFETs) and/or 1447:Sequential access 1401:Read only storage 1314: 1313: 1291:Main application 1017:disaster recovery 945:optical jukeboxes 868:operating systems 804:devices, such as 775:auxiliary storage 767:Secondary storage 762:Secondary storage 729:secondary storage 725:secondary storage 508:secondary storage 437:read-write memory 403:control circuitry 195:Analytical Engine 184:storage hierarchy 67: 66: 62: 16:(Redirected from 5238: 5089: 5088: 5005: 5004: 4984: 4977: 4970: 4961: 4960: 4832: 4831: 4483:Optical trackpad 4448:Pointing devices 4444: 4443: 4420: 4413: 4406: 4397: 4396: 4386: 4384: 4348: 4347: 4340: 4334: 4333: 4285: 4279: 4278: 4276: 4274: 4259: 4253: 4252: 4250: 4248: 4229: 4223: 4222: 4220: 4218: 4198: 4192: 4191: 4189: 4187: 4176:sciencedaily.com 4168: 4162: 4161: 4149: 4143: 4142: 4135: 4129: 4128: 4118: 4092: 4068: 4059: 4058: 4053:. Archived from 4047: 4041: 4040: 4029: 4023: 4022: 4020: 4013: 4005: 3999: 3998: 3996: 3994: 3975: 3969: 3968: 3966: 3964: 3949: 3943: 3942: 3940: 3938: 3923: 3917: 3916: 3914: 3912: 3907:on 18 March 2012 3903:. Archived from 3893: 3887: 3886: 3884: 3882: 3863: 3857: 3856: 3845: 3839: 3838: 3827: 3821: 3820: 3818: 3816: 3801: 3795: 3794: 3792: 3790: 3779: 3773: 3772: 3770: 3768: 3762: 3755: 3747: 3741: 3740: 3738: 3729: 3723: 3722: 3710: 3701: 3700: 3698: 3696: 3689:tomshardware.com 3681: 3675: 3674: 3672: 3670: 3651: 3645: 3644: 3642: 3640: 3624: 3618: 3617: 3615: 3613: 3597: 3591: 3590: 3585:. Archived from 3575: 3569: 3568: 3563:. Archived from 3557: 3551: 3545: 3543: 3541: 3520: 3514: 3513: 3511: 3509: 3500:. Archived from 3489: 3483: 3482: 3480: 3478: 3472: 3465: 3457: 3451: 3450: 3448: 3431: 3417: 3411: 3410: 3391: 3385: 3384: 3382: 3380: 3371:. Archived from 3361: 3355: 3354: 3347: 3341: 3335: 3329: 3328: 3301:(3rd ed.). 3300: 3290: 3276: 3275: 3270:. Archived from 3254: 3253: 3238: 3235: 3197:Write protection 3114:Data storage tag 2780:Molecular memory 2693:cathode-ray tube 2562: 2555: 2548: 2539: 2538: 2111: 2104: 2097: 2088: 2087: 2058:thin-film memory 2054:core rope memory 1989:Magnetic storage 1886:Magnetic storage 1879: 1872: 1865: 1856: 1855: 1841:desktop computer 1722:hard disk drives 1489:operating system 1473:File addressable 1437:hard disk drives 1251:Price per space 1225:Error detection 1087:Linear tape-open 1060: 1056: 998:Off-line storage 993:Off-line storage 964:nearline storage 924:Tertiary storage 903:Nearline storage 897:Tertiary storage 814:USB flash drives 782:hard disk drives 756:byte-addressable 733:tertiary storage 713:embedded systems 696:read-only memory 674:or other tasks. 461:hard disk drives 457:tertiary storage 385:Memory hierarchy 365:security reasons 357:Data compression 260:digital computer 144:storage instead. 94:. An example of 58: 38: 37: 30: 21: 18:Computer storage 5246: 5245: 5241: 5240: 5239: 5237: 5236: 5235: 5216: 5215: 5214: 5205: 5174: 5138: 5074: 5048: 5032: 5000:Volatile memory 4994: 4988: 4958: 4953: 4923: 4871: 4821: 4699: 4693:USB flash drive 4642: 4635: 4574: 4507: 4461:Game controller 4456:Graphics tablet 4433: 4424: 4357: 4355:Further reading 4352: 4351: 4342: 4341: 4337: 4286: 4282: 4272: 4270: 4261: 4260: 4256: 4246: 4244: 4231: 4230: 4226: 4216: 4214: 4199: 4195: 4185: 4183: 4182:on 1 March 2009 4170: 4169: 4165: 4150: 4146: 4137: 4136: 4132: 4069: 4062: 4049: 4048: 4044: 4031: 4030: 4026: 4018: 4011: 4007: 4006: 4002: 3992: 3990: 3977: 3976: 3972: 3962: 3960: 3951: 3950: 3946: 3936: 3934: 3925: 3924: 3920: 3910: 3908: 3895: 3894: 3890: 3880: 3878: 3865: 3864: 3860: 3847: 3846: 3842: 3829: 3828: 3824: 3814: 3812: 3803: 3802: 3798: 3788: 3786: 3781: 3780: 3776: 3766: 3764: 3760: 3753: 3749: 3748: 3744: 3736: 3730: 3726: 3711: 3704: 3694: 3692: 3683: 3682: 3678: 3668: 3666: 3659:The tech report 3653: 3652: 3648: 3638: 3636: 3625: 3621: 3611: 3609: 3598: 3594: 3577: 3576: 3572: 3559: 3558: 3554: 3539: 3537: 3536:on 2 March 2009 3521: 3517: 3507: 3505: 3490: 3486: 3476: 3474: 3470: 3463: 3459: 3458: 3454: 3446: 3440: 3429: 3418: 3414: 3407: 3393: 3392: 3388: 3378: 3376: 3363: 3362: 3358: 3349: 3348: 3344: 3336: 3332: 3317: 3291: 3282: 3260: 3251: 3249: 3247: 3242: 3241: 3236: 3232: 3227: 3210: 3167:Removable media 3090: 3019: 3014: 2959: 2957:Robotic storage 2895: 2838: 2832: 2824:Main articles: 2822: 2817: 2681: 2651: 2646: 2599: 2572: 2566: 2536: 2419:Optical storage 2416: 2411: 2394:Laser turntable 2382: 2344: 2261: 2229: 2179: 2159: 2121: 2118:Optical storage 2115: 2085: 2067:Tertiary (e.g. 2046:magnetic memory 2034:Carousel memory 2020:Hard disk drive 1986: 1981: 1889: 1883: 1853: 1771: 1765: 1756: 1703: 1701:Error detection 1672: 1650: 1629: 1559: 1526: 1459: 1419: 1360: 1326:Volatile memory 1319: 1271:Price per unit 1171:None (instant) 1168:None (instant) 1067:Hard disk drive 1063:Characteristic 1034: 1002:processing unit 995: 928:tertiary memory 909: 899: 802:optical storage 771:external memory 769:(also known as 764: 721:primary storage 640:secondary cache 627:Processor cache 556:early computers 541:internal memory 535:(also known as 533:Primary storage 530: 528:Computer memory 524: 522:Primary storage 512:external memory 504:internal memory 387: 381: 351:error detection 256: 223: 191:Charles Babbage 169:recording media 167:components and 96:primary storage 76: 63: 39: 35: 28: 23: 22: 15: 12: 11: 5: 5244: 5234: 5233: 5228: 5211: 5210: 5207: 5206: 5204: 5203: 5201:Twistor memory 5198: 5193: 5188: 5182: 5180: 5176: 5175: 5173: 5172: 5167: 5162: 5157: 5152: 5146: 5144: 5140: 5139: 5137: 5136: 5131: 5126: 5121: 5116: 5111: 5106: 5095: 5093: 5086: 5080: 5079: 5076: 5075: 5073: 5072: 5067: 5065:Selectron tube 5062: 5056: 5054: 5050: 5049: 5047: 5046: 5040: 5038: 5034: 5033: 5031: 5030: 5025: 5024: 5023: 5011: 5009: 5002: 4996: 4995: 4987: 4986: 4979: 4972: 4964: 4955: 4954: 4952: 4951: 4946: 4941: 4935: 4933: 4929: 4928: 4925: 4924: 4922: 4921: 4916: 4911: 4906: 4901: 4896: 4891: 4886: 4879: 4877: 4873: 4872: 4870: 4869: 4864: 4859: 4854: 4849: 4844: 4838: 4836: 4829: 4823: 4822: 4820: 4819: 4817:Expansion card 4814: 4809: 4804: 4803: 4802: 4797: 4787: 4786: 4785: 4775: 4774: 4773: 4768: 4754: 4744: 4743: 4742: 4737: 4727: 4722: 4721: 4720: 4718:Microprocessor 4709: 4707: 4701: 4700: 4698: 4697: 4696: 4695: 4690: 4680: 4679: 4678: 4673: 4668: 4658: 4653: 4647: 4645: 4637: 4636: 4634: 4633: 4628: 4623: 4618: 4617: 4616: 4606: 4601: 4600: 4599: 4588: 4586: 4584:Output devices 4580: 4579: 4576: 4575: 4573: 4572: 4571: 4570: 4560: 4559: 4558: 4548: 4543: 4538: 4537: 4536: 4526: 4521: 4515: 4513: 4509: 4508: 4506: 4505: 4500: 4495: 4490: 4488:Pointing stick 4485: 4480: 4479: 4478: 4468: 4463: 4458: 4452: 4450: 4441: 4435: 4434: 4423: 4422: 4415: 4408: 4400: 4394: 4393: 4387: 4356: 4353: 4350: 4349: 4335: 4280: 4254: 4224: 4193: 4163: 4144: 4130: 4060: 4042: 4024: 4000: 3970: 3959:on 27 May 2013 3944: 3933:on 6 June 2013 3918: 3888: 3858: 3840: 3822: 3796: 3774: 3742: 3724: 3702: 3676: 3646: 3619: 3592: 3570: 3552: 3515: 3484: 3452: 3438: 3412: 3405: 3386: 3356: 3342: 3330: 3315: 3279: 3278: 3246: 3243: 3240: 3239: 3229: 3228: 3226: 3223: 3222: 3221: 3216: 3209: 3206: 3205: 3204: 3199: 3194: 3189: 3184: 3179: 3174: 3169: 3164: 3159: 3154: 3149: 3144: 3139: 3138: 3137: 3132: 3122: 3117: 3111: 3106: 3101: 3096: 3089: 3086: 3085: 3084: 3078: 3076:Stable storage 3073: 3068: 3063: 3062: 3061: 3059:Virtual memory 3056: 3046: 3041: 3036: 3034:Memory latency 3031: 3025: 3018: 3015: 3013: 3010: 3008:back to disk. 2963:tape libraries 2958: 2955: 2954: 2953: 2943: 2913: 2894: 2891: 2886: 2885: 2853: 2826:Disk mirroring 2821: 2818: 2816: 2813: 2812: 2811: 2804: 2798: 2797: 2794: 2790: 2789: 2782: 2776: 2775: 2760: 2754: 2753: 2741: 2735: 2734: 2730: 2724: 2723: 2709: 2705: 2704: 2697:Selectron tube 2685: 2680: 2677: 2673:matrix barcode 2648: 2647: 2645: 2644: 2638: 2632: 2626: 2620: 2614: 2607: 2605: 2601: 2600: 2598: 2597: 2591: 2580: 2578: 2574: 2573: 2565: 2564: 2557: 2550: 2542: 2535: 2532: 2504: 2503: 2493: 2471: 2453: 2421:, the typical 2413: 2412: 2410: 2409: 2403: 2397: 2390: 2388: 2387:Optical Assist 2384: 2383: 2381: 2380: 2374: 2368: 2362: 2355: 2353: 2346: 2345: 2343: 2342: 2336: 2330: 2324: 2318: 2312: 2306: 2300: 2294: 2288: 2287:(20th century) 2282: 2281:(20th century) 2276: 2269: 2267: 2263: 2262: 2260: 2259: 2253: 2247: 2240: 2238: 2231: 2230: 2228: 2227: 2221: 2215: 2209: 2203: 2197: 2190: 2188: 2181: 2180: 2178: 2177: 2170: 2168: 2161: 2160: 2158: 2157: 2151: 2145: 2139: 2132: 2130: 2123: 2122: 2114: 2113: 2106: 2099: 2091: 2084: 2081: 2076: 2075: 2072: 2065: 2062:twistor memory 2038: 2037: 2031: 2025: 2024: 2023: 2017: 1983: 1982: 1980: 1979: 1973: 1967: 1961: 1955: 1949: 1943: 1937: 1931: 1925: 1919: 1913: 1907: 1901: 1894: 1891: 1890: 1882: 1881: 1874: 1867: 1859: 1852: 1849: 1798:MOS capacitors 1767:Main article: 1764: 1761: 1755: 1752: 1748:optical drives 1738:The health of 1702: 1699: 1671: 1668: 1649: 1646: 1645: 1644: 1633: 1628: 1625: 1613: 1612: 1605: 1602: 1599: 1596: 1589: 1584: 1565: 1558: 1555: 1554: 1553: 1550: 1545: 1530: 1525: 1522: 1521: 1520: 1501: 1496: 1485:human-readable 1475: 1470: 1467:memory address 1463: 1458: 1457:Addressability 1455: 1454: 1453: 1449: 1444: 1433:flash memories 1425: 1418: 1415: 1414: 1413: 1402: 1399: 1385: 1382: 1371: 1368: 1364: 1359: 1356: 1318: 1315: 1312: 1311: 1308: 1305: 1302: 1295: 1292: 1288: 1287: 1284: 1281: 1278: 1275: 1272: 1268: 1267: 1264: 1261: 1258: 1255: 1252: 1248: 1247: 1244: 1241: 1238: 1233: 1226: 1222: 1221: 1218: 1213: 1210: 1205: 1198: 1197: 1194: 1191: 1186: 1183: 1180: 1176: 1175: 1172: 1169: 1166: 1163: 1157: 1156:(access time) 1150: 1149: 1146: 1143: 1140: 1137: 1134: 1133:Random access 1130: 1129: 1126: 1123: 1120: 1117: 1114: 1110: 1109: 1108:Magnetic tape 1106: 1105:Semiconductor 1103: 1097: 1096:Magnetic disk 1094: 1090: 1089: 1084: 1079: 1074: 1069: 1064: 1033: 1030: 994: 991: 987:tape libraries 979: 978: 975: 972: 941:tape libraries 898: 895: 872:virtual memory 866:Most computer 763: 760: 754:, are usually 672:virtual memory 660:memory address 644: 643: 624: 568:magnetic drums 566:, or rotating 564:Williams tubes 554:Historically, 526:Main article: 523: 520: 480:central memory 474:Historically, 411:home computers 383:Main article: 380: 377: 255: 252: 222: 219: 65: 64: 42: 40: 33: 26: 9: 6: 4: 3: 2: 5243: 5232: 5229: 5227: 5224: 5223: 5221: 5202: 5199: 5197: 5194: 5192: 5189: 5187: 5186:Bubble memory 5184: 5183: 5181: 5177: 5171: 5168: 5166: 5163: 5161: 5158: 5156: 5153: 5151: 5148: 5147: 5145: 5141: 5135: 5132: 5130: 5127: 5125: 5122: 5120: 5117: 5115: 5112: 5110: 5107: 5104: 5100: 5097: 5096: 5094: 5090: 5087: 5085: 5081: 5071: 5070:Williams tube 5068: 5066: 5063: 5061: 5058: 5057: 5055: 5051: 5045: 5042: 5041: 5039: 5035: 5029: 5026: 5022: 5018: 5017: 5016: 5013: 5012: 5010: 5006: 5003: 5001: 4997: 4992: 4985: 4980: 4978: 4973: 4971: 4966: 4965: 4962: 4950: 4947: 4945: 4942: 4940: 4937: 4936: 4934: 4930: 4920: 4917: 4915: 4912: 4910: 4907: 4905: 4902: 4900: 4897: 4895: 4892: 4890: 4889:Parallel port 4887: 4884: 4881: 4880: 4878: 4874: 4868: 4865: 4863: 4860: 4858: 4855: 4853: 4850: 4848: 4845: 4843: 4840: 4839: 4837: 4833: 4830: 4828: 4824: 4818: 4815: 4813: 4810: 4808: 4805: 4801: 4798: 4796: 4793: 4792: 4791: 4788: 4784: 4781: 4780: 4779: 4776: 4772: 4769: 4766: 4762: 4758: 4755: 4753: 4750: 4749: 4748: 4745: 4741: 4738: 4736: 4733: 4732: 4731: 4728: 4726: 4723: 4719: 4716: 4715: 4714: 4711: 4710: 4708: 4706: 4705:Computer case 4702: 4694: 4691: 4689: 4686: 4685: 4684: 4681: 4677: 4674: 4672: 4669: 4667: 4664: 4663: 4662: 4659: 4657: 4654: 4652: 4649: 4648: 4646: 4644: 4638: 4632: 4631:Graphics card 4629: 4627: 4624: 4622: 4619: 4615: 4612: 4611: 4610: 4607: 4605: 4602: 4598: 4595: 4594: 4593: 4590: 4589: 4587: 4585: 4581: 4569: 4566: 4565: 4564: 4561: 4557: 4554: 4553: 4552: 4549: 4547: 4544: 4542: 4539: 4535: 4532: 4531: 4530: 4529:Graphics card 4527: 4525: 4524:Image scanner 4522: 4520: 4517: 4516: 4514: 4510: 4504: 4501: 4499: 4496: 4494: 4491: 4489: 4486: 4484: 4481: 4477: 4474: 4473: 4472: 4469: 4467: 4464: 4462: 4459: 4457: 4454: 4453: 4451: 4449: 4445: 4442: 4440: 4439:Input devices 4436: 4432: 4429: 4421: 4416: 4414: 4409: 4407: 4402: 4401: 4398: 4391: 4388: 4383: 4378: 4375:: 1433–1440. 4374: 4370: 4369: 4364: 4359: 4358: 4345: 4339: 4331: 4327: 4323: 4319: 4315: 4311: 4307: 4303: 4299: 4295: 4291: 4284: 4268: 4264: 4258: 4242: 4238: 4234: 4228: 4212: 4208: 4204: 4197: 4181: 4177: 4173: 4167: 4159: 4155: 4148: 4140: 4134: 4126: 4122: 4117: 4112: 4108: 4104: 4100: 4096: 4091: 4086: 4082: 4078: 4074: 4067: 4065: 4056: 4052: 4046: 4038: 4034: 4028: 4017: 4010: 4004: 3988: 3984: 3980: 3974: 3958: 3954: 3948: 3932: 3928: 3922: 3906: 3902: 3898: 3892: 3876: 3872: 3868: 3862: 3854: 3850: 3844: 3836: 3832: 3826: 3810: 3806: 3800: 3784: 3778: 3759: 3752: 3746: 3735: 3728: 3720: 3716: 3709: 3707: 3690: 3686: 3680: 3664: 3660: 3656: 3650: 3634: 3630: 3623: 3607: 3603: 3596: 3588: 3584: 3580: 3574: 3566: 3562: 3556: 3549: 3535: 3531: 3530: 3525: 3519: 3503: 3499: 3495: 3488: 3469: 3462: 3456: 3445: 3441: 3435: 3428: 3427: 3422: 3416: 3408: 3402: 3398: 3397: 3390: 3374: 3370: 3366: 3360: 3352: 3346: 3339: 3334: 3326: 3322: 3318: 3316:1-55860-604-1 3312: 3308: 3304: 3299: 3298: 3289: 3287: 3285: 3280: 3277: 3273: 3269: 3265: 3264: 3258: 3234: 3230: 3220: 3217: 3215: 3212: 3211: 3203: 3200: 3198: 3195: 3193: 3190: 3188: 3185: 3183: 3180: 3178: 3175: 3173: 3170: 3168: 3165: 3163: 3160: 3158: 3155: 3153: 3150: 3148: 3145: 3143: 3140: 3136: 3133: 3131: 3128: 3127: 3126: 3123: 3121: 3118: 3115: 3112: 3110: 3107: 3105: 3102: 3100: 3097: 3095: 3094:Cloud storage 3092: 3091: 3082: 3079: 3077: 3074: 3072: 3069: 3067: 3064: 3060: 3057: 3055: 3052: 3051: 3050: 3047: 3045: 3042: 3040: 3037: 3035: 3032: 3029: 3026: 3024: 3021: 3020: 3009: 3007: 3003: 2999: 2995: 2990: 2988: 2984: 2978: 2976: 2972: 2968: 2964: 2951: 2950:Fibre Channel 2947: 2944: 2941: 2937: 2933: 2929: 2925: 2921: 2917: 2914: 2911: 2907: 2904: 2903: 2902: 2900: 2890: 2883: 2879: 2875: 2871: 2867: 2863: 2862: 2857: 2854: 2851: 2850:(replication) 2849: 2844: 2843: 2842: 2837: 2831: 2827: 2809: 2805: 2803: 2800: 2799: 2795: 2792: 2791: 2787: 2783: 2781: 2778: 2777: 2773: 2769: 2768:photopolymers 2765: 2761: 2759: 2756: 2755: 2750: 2746: 2742: 2740: 2737: 2736: 2731: 2729: 2726: 2725: 2721: 2717: 2713: 2710: 2707: 2706: 2702: 2699:used a large 2698: 2694: 2690: 2689:Williams tube 2686: 2683: 2682: 2676: 2674: 2669: 2667: 2663: 2662:punched cards 2659: 2655: 2642: 2639: 2636: 2633: 2630: 2627: 2624: 2621: 2618: 2615: 2612: 2609: 2608: 2606: 2602: 2595: 2592: 2590:(c. 3000 BCE) 2589: 2585: 2582: 2581: 2579: 2575: 2570: 2563: 2558: 2556: 2551: 2549: 2544: 2543: 2540: 2531: 2528: 2526: 2522: 2520: 2516: 2512: 2511:ferromagnetic 2508: 2501: 2500:BD-R or BD-RE 2497: 2494: 2491: 2487: 2483: 2479: 2475: 2472: 2469: 2465: 2461: 2457: 2454: 2451: 2447: 2443: 2439: 2436: 2435: 2434: 2432: 2428: 2424: 2420: 2407: 2404: 2401: 2398: 2395: 2392: 2391: 2389: 2385: 2378: 2375: 2372: 2369: 2366: 2363: 2360: 2357: 2356: 2354: 2351: 2347: 2340: 2337: 2334: 2331: 2328: 2325: 2322: 2319: 2316: 2313: 2310: 2307: 2304: 2301: 2298: 2295: 2292: 2289: 2286: 2283: 2280: 2277: 2274: 2271: 2270: 2268: 2264: 2257: 2254: 2251: 2248: 2245: 2242: 2241: 2239: 2236: 2232: 2225: 2222: 2219: 2216: 2213: 2210: 2207: 2204: 2201: 2198: 2195: 2192: 2191: 2189: 2186: 2182: 2175: 2172: 2171: 2169: 2166: 2162: 2155: 2152: 2149: 2146: 2143: 2140: 2137: 2134: 2133: 2131: 2128: 2124: 2119: 2112: 2107: 2105: 2100: 2098: 2093: 2092: 2089: 2080: 2073: 2070: 2066: 2063: 2059: 2055: 2051: 2047: 2043: 2042: 2041: 2035: 2032: 2029: 2028:Magnetic tape 2026: 2021: 2018: 2015: 2012: 2011: 2009: 2008:Magnetic disk 2006: 2005: 2004: 2002: 1998: 1994: 1993:magnetization 1990: 1977: 1974: 1971: 1968: 1965: 1962: 1959: 1956: 1953: 1950: 1947: 1944: 1941: 1938: 1935: 1932: 1929: 1926: 1923: 1920: 1917: 1914: 1911: 1908: 1905: 1902: 1899: 1896: 1895: 1892: 1887: 1880: 1875: 1873: 1868: 1866: 1861: 1860: 1857: 1848: 1846: 1842: 1838: 1833: 1830: 1826: 1825:floating-gate 1822: 1818: 1813: 1811: 1807: 1803: 1799: 1795: 1791: 1787: 1783: 1779: 1778:semiconductor 1775: 1770: 1763:Semiconductor 1760: 1754:Storage media 1751: 1749: 1745: 1741: 1740:optical media 1736: 1734: 1729: 1727: 1723: 1715: 1711: 1707: 1698: 1696: 1692: 1691:head crashing 1687: 1685: 1676: 1667: 1665: 1660: 1658: 1654: 1642: 1638: 1634: 1631: 1630: 1624: 1622: 1618: 1610: 1606: 1603: 1600: 1597: 1594: 1590: 1588: 1585: 1582: 1578: 1574: 1571:is typically 1570: 1566: 1564: 1561: 1560: 1551: 1549: 1546: 1543: 1539: 1535: 1531: 1528: 1527: 1518: 1514: 1510: 1506: 1502: 1500: 1497: 1494: 1490: 1486: 1482: 1481: 1476: 1474: 1471: 1468: 1464: 1461: 1460: 1450: 1448: 1445: 1442: 1438: 1434: 1430: 1426: 1424: 1423:Random access 1421: 1420: 1417:Accessibility 1411: 1407: 1403: 1400: 1397: 1393: 1389: 1386: 1383: 1380: 1376: 1372: 1369: 1365: 1362: 1361: 1355: 1353: 1352:EMC Symmetrix 1349: 1344: 1342: 1338: 1334: 1330: 1327: 1323: 1309: 1306: 1303: 1301:distribution 1300: 1296: 1293: 1290: 1289: 1285: 1282: 1279: 1276: 1273: 1270: 1269: 1265: 1262: 1259: 1256: 1253: 1250: 1249: 1245: 1242: 1239: 1237: 1234: 1231: 1227: 1224: 1223: 1219: 1217: 1211: 1209: 1206: 1204: 1200: 1199: 1195: 1192: 1190: 1187: 1184: 1181: 1178: 1177: 1173: 1170: 1167: 1164: 1161: 1158: 1155: 1152: 1151: 1147: 1144: 1141: 1138: 1135: 1132: 1131: 1127: 1124: 1121: 1118: 1115: 1112: 1111: 1107: 1101: 1098: 1095: 1092: 1091: 1088: 1085: 1083: 1080: 1078: 1075: 1073: 1070: 1068: 1065: 1062: 1061: 1055: 1049: 1046: 1043: 1038: 1029: 1025: 1022: 1018: 1013: 1009: 1005: 1003: 999: 990: 988: 984: 976: 973: 970: 969: 968: 966: 965: 959: 957: 953: 948: 946: 942: 937: 934:(insert) and 933: 929: 925: 918: 913: 908: 907:Cloud storage 904: 894: 892: 888: 884: 879: 877: 873: 869: 864: 862: 858: 854: 850: 845: 842: 837: 835: 831: 830:punched cards 827: 823: 822:magnetic tape 819: 815: 811: 807: 803: 799: 795: 791: 787: 783: 778: 776: 772: 768: 759: 757: 753: 749: 745: 741: 736: 734: 730: 726: 722: 717: 714: 710: 705: 703: 702: 701:random access 697: 693: 689: 686:) is used to 685: 681: 675: 673: 669: 665: 661: 657: 653: 649: 641: 637: 636:primary cache 633: 628: 625: 622: 618: 614: 611: 610: 609: 606: 604: 600: 596: 592: 588: 583: 581: 577: 573: 569: 565: 561: 557: 552: 550: 546: 542: 538: 534: 529: 519: 517: 513: 509: 505: 501: 497: 493: 489: 485: 481: 477: 472: 470: 466: 462: 459:), typically 458: 454: 450: 446: 442: 438: 435: 434:semiconductor 431: 426: 424: 420: 412: 408: 404: 400: 396: 391: 386: 376: 374: 370: 366: 361: 358: 354: 352: 348: 344: 340: 335: 330: 328: 324: 320: 316: 312: 308: 304: 300: 295: 293: 289: 285: 281: 277: 273: 269: 265: 261: 251: 249: 245: 241: 237: 233: 229: 221:Functionality 218: 216: 212: 208: 204: 200: 199:Percy Ludgate 196: 192: 187: 185: 181: 176: 174: 170: 166: 162: 158: 150: 143: 139: 135: 131: 128: 123: 116: 112: 109: 104: 97: 93: 90:mounted in a 89: 85: 80: 74: 69: 61: 56: 52: 48: 47: 41: 32: 31: 19: 5124:Flash memory 4993:technologies 4795:Power MOSFET 4778:Power supply 4747:Data storage 4746: 4683:Flash memory 4661:Optical disc 4643:data storage 4372: 4366: 4338: 4297: 4293: 4283: 4271:. Retrieved 4257: 4245:. Retrieved 4236: 4227: 4215:. Retrieved 4207:The Atlantic 4206: 4196: 4184:. Retrieved 4180:the original 4175: 4166: 4157: 4147: 4133: 4080: 4076: 4055:the original 4045: 4036: 4027: 4003: 3991:. Retrieved 3987:the original 3982: 3973: 3961:. Retrieved 3957:the original 3947: 3935:. Retrieved 3931:the original 3921: 3909:. Retrieved 3905:the original 3900: 3891: 3879:. Retrieved 3875:the original 3871:Extreme tech 3870: 3861: 3852: 3843: 3834: 3825: 3813:. Retrieved 3809:the original 3799: 3787:. Retrieved 3777: 3765:. Retrieved 3745: 3727: 3719:the original 3693:. Retrieved 3688: 3679: 3667:. Retrieved 3663:the original 3658: 3649: 3637:. Retrieved 3622: 3610:. Retrieved 3595: 3587:the original 3582: 3573: 3565:the original 3555: 3538:. Retrieved 3534:the original 3528: 3518: 3506:. Retrieved 3502:the original 3497: 3487: 3475:. Retrieved 3455: 3425: 3421:J. S. Vitter 3415: 3395: 3389: 3377:. Retrieved 3373:the original 3368: 3359: 3345: 3337: 3333: 3296: 3272:the original 3262: 3248: 3233: 3192:Write buffer 3142:Flash memory 3120:Disk utility 3039:Mass storage 3005: 3001: 2991: 2979: 2975:autochangers 2960: 2922:, a private 2896: 2887: 2881: 2877: 2876:are common. 2873: 2869: 2865: 2859: 2855: 2845: 2839: 2752:information. 2728:Optical tape 2670: 2652: 2623:Punched card 2617:Punched tape 2529: 2523: 2518: 2515:non-volatile 2514: 2505: 2431:non-volatile 2430: 2423:optical disc 2417: 2285:Optical disc 2279:Optical tape 2266:Discontinued 2235:Compact disc 2077: 2039: 2001:non-volatile 2000: 1997:magnetically 1987: 1916:Ferrite core 1834: 1829:flash memory 1814: 1806:non-volatile 1805: 1801: 1790:memory cells 1772: 1757: 1737: 1730: 1719: 1688: 1681: 1661: 1651: 1614: 1609:failure rate 1529:Raw capacity 1478: 1406:mask ROM ICs 1345: 1331: 1320: 1228:Diagnostic ( 1077:Flash memory 1072:Optical disc 1052: 1026: 1006: 997: 996: 980: 962: 960: 949: 935: 931: 927: 923: 922: 917:tape library 880: 865: 846: 838: 818:floppy disks 794:milliseconds 779: 774: 770: 766: 765: 737: 732: 728: 724: 720: 718: 708: 706: 699: 691: 676: 664:memory cells 647: 645: 639: 635: 607: 599:write buffer 584: 553: 548: 545:prime memory 544: 540: 536: 532: 531: 515: 511: 507: 503: 500:real storage 499: 495: 491: 488:core storage 487: 483: 479: 475: 473: 469:non-volatile 465:optical disc 444: 439:, typically 429: 427: 416: 413:around 2005. 407:input/output 362: 355: 331: 296: 282:, or simply 279: 257: 244:reprogrammed 240:instructions 224: 207:control unit 188: 177: 173:digital data 160: 156: 155: 141: 138:tape library 133: 114: 95: 73:Data storage 68: 59: 44: 5191:Drum memory 4894:Serial port 4885:(IEEE 1394) 4862:DisplayPort 4852:Thunderbolt 4725:Motherboard 4688:Memory card 4656:Floppy disk 4498:Touchscreen 3815:28 December 3789:28 December 3767:28 December 3583:Simple tech 3125:File system 3054:Memory leak 2971:autoloaders 2930:, over the 2808:nucleotides 2716:sound waves 2701:vacuum tube 2619:(mid-1800s) 2427:laser diode 2050:core memory 2014:Floppy disk 1958:Floppy disk 1928:Stripe card 1641:memory wall 1604:Reliability 1598:Granularity 1577:millisecond 1557:Performance 1540:(e.g. 10.4 1493:abstraction 1179:Controller 1113:Volatility 1093:Technology 956:robotic arm 857:directories 849:file system 798:nanoseconds 790:access time 652:address bus 560:delay lines 537:main memory 496:main memory 484:core memory 369:credit card 262:represents 236:Von Neumann 228:calculators 5220:Categories 5179:Historical 5053:Historical 4641:Removable 4626:Sound card 4556:Sound chip 4551:Sound card 4541:Microphone 4431:components 4201:Yong, Ed. 4090:1611.08205 3245:References 3187:Wait state 3147:Geoplexing 2942:protocols. 2834:See also: 2820:Redundancy 2658:paper tape 2611:Index card 1627:Energy use 1587:Throughput 1573:nanosecond 1358:Mutability 1317:Volatility 1307:Real-time 1263:Very high 1230:S.M.A.R.T. 1208:Head crash 901:See also: 826:paper tape 784:(HDDs) or 719:Recently, 648:memory bus 595:disk cache 311:multimedia 266:using the 5103:3D XPoint 5021:DDR SDRAM 4904:PS/2 port 4899:Game port 4812:Fax modem 4651:Disk pack 4503:Trackball 4466:Light pen 4083:: 13406. 3835:Backblaze 3785:. Lwn.net 3540:8 October 3508:16 August 3303:Amsterdam 3202:Cold data 3006:retrieved 3002:migrating 2987:petabytes 2983:terabytes 2952:networks. 2848:mirroring 2577:Antiquity 2406:Super DLT 2400:Floptical 2291:LaserDisc 2273:Microform 1976:Racetrack 1940:Thin film 1922:Hard disk 1542:megabytes 1517:CPU cache 1337:refreshed 1299:hard copy 1280:Moderate 1274:Moderate 1216:Circuitry 1203:data loss 1196:External 1193:Internal 1185:External 1182:Internal 1125:Volatile 1058:Overview 839:Once the 834:RAM disks 748:NOR flash 709:read only 692:secondary 688:bootstrap 603:RAM drive 453:secondary 419:bandwidth 373:encrypted 343:radiation 303:character 297:Data are 292:megabytes 258:A modern 217:on data. 125:160 115:secondary 4883:FireWire 4876:Obsolete 4842:Ethernet 4621:Speakers 4519:Keyboard 4493:Touchpad 4428:computer 4330:13470340 4322:28254941 4267:Archived 4241:Archived 4237:phys.org 4211:Archived 4125:27882917 4016:Archived 3758:Archived 3639:2 August 3633:Archived 3612:2 August 3606:Archived 3468:Archived 3444:Archived 3423:(2008). 3325:56213091 3012:See also 2940:CIFS/SMB 2932:Internet 2910:retronym 2764:crystals 2695:, and a 2666:Barcodes 2596:(105 CE) 2365:MiniDisc 2315:DataPlay 2224:DVD-R DL 2218:DVD+R DL 2154:BD-RE XL 2069:NCR CRAM 1851:Magnetic 1837:notebook 1802:volatile 1648:Security 1593:bit rate 1524:Capacity 1513:hardware 1509:software 1452:storage. 1367:storage. 1246:Unknown 1189:Internal 1162:(swift) 1008:Off-line 952:database 936:dismount 915:A large 861:metadata 656:data bus 591:volatile 339:bit flip 209:and the 165:computer 142:tertiary 134:off-line 117:storage. 106:15 92:computer 5092:Current 5008:Current 4932:Related 4835:Current 4676:Blu-ray 4614:Plotter 4609:Printer 4592:Monitor 4568:Softcam 4476:Optical 4302:Bibcode 4294:Science 4273:3 March 4247:3 March 4217:3 March 4186:18 June 4116:5123013 4095:Bibcode 3993:18 June 3963:18 June 3937:18 June 3911:18 June 3881:18 June 3695:18 June 3669:18 June 3477:18 June 3379:18 June 3338:Storage 3177:Spindle 2994:backups 2846:Device 2786:polymer 2720:mercury 2691:used a 2641:Barcode 2637:(1930s) 2625:(1880s) 2613:(1640s) 2588:papyrus 2584:Writing 2486:DVD-RAM 2371:MD Data 2361:(1980s) 2359:MO disc 2327:ProData 2148:BD-R XL 2127:Blu-ray 2083:Optical 2060:and/or 1966:(~1970) 1954:(~1968) 1952:Twistor 1800:. Both 1780:-based 1563:Latency 1441:latency 1154:Latency 445:Storage 423:latency 299:encoded 82:1 55:Discuss 5143:Future 5114:EEPROM 5037:Future 5019:e.g., 4790:MOSFET 4730:Memory 4597:Screen 4563:Webcam 4426:Basic 4328: 4320: 4123: 4113: 3436: 3403: 3323: 3313: 3083:(SRAM) 3030:(DRAM) 2878:n>2 2774:(HVD). 2643:(1948) 2631:(1904) 2604:Modern 2482:DVD+RW 2478:DVD-RW 2450:BD-ROM 2442:CD-ROM 2408:(1998) 2402:(1991) 2396:(1986) 2379:(2004) 2373:(1993) 2367:(1992) 2352:(1877) 2341:(2006) 2339:HD DVD 2335:(2004) 2329:(2003) 2323:(2003) 2317:(2002) 2311:(1999) 2309:MIL-CD 2305:(1997) 2303:GD-ROM 2299:(1979) 2293:(1978) 2275:(1870) 2258:(1997) 2252:(1991) 2246:(1988) 2237:(1982) 2226:(2005) 2220:(2004) 2214:(2002) 2208:(2001) 2206:DVD+RW 2202:(1999) 2200:DVD-RW 2196:(1997) 2187:(1995) 2176:(2004) 2167:(2003) 2156:(2010) 2150:(2010) 2144:(2006) 2138:(2006) 2129:(2006) 1978:(2008) 1972:(1995) 1964:Bubble 1960:(1969) 1948:(1962) 1942:(1962) 1936:(1956) 1930:(1956) 1924:(1956) 1918:(1949) 1912:(1932) 1906:(1928) 1900:(1898) 1788:(MOS) 1617:hdparm 1581:second 1410:CD-ROM 1160:~15 ms 1042:laptop 832:, and 750:, and 744:EEPROM 654:and a 549:memory 476:memory 430:memory 334:random 327:MPEG-4 51:merged 5170:SONOS 5150:FeRAM 5119:EPROM 5109:EAROM 5044:Z-RAM 4909:eSATA 4827:Ports 4512:Other 4471:Mouse 4326:S2CID 4158:Wired 4085:arXiv 4019:(PDF) 4012:(PDF) 3761:(PDF) 3754:(PDF) 3737:(PDF) 3471:(PDF) 3464:(PDF) 3447:(PDF) 3430:(PDF) 3259:from 3225:Notes 2714:used 2594:Paper 2571:media 2534:Paper 2490:BD-RE 2474:CD-RW 2464:DVD+R 2460:DVD-R 2377:Hi-MD 2256:CD-RW 2212:DVD+R 2194:DVD-R 2142:BD-RE 2120:media 2048:, or 1995:on a 1888:media 1776:uses 1714:DVD+R 1712:on a 1664:SPARC 1538:bytes 1480:files 1375:CD-RW 1283:High 1260:High 1102:beam 1100:Laser 932:mount 876:pages 853:files 558:used 543:, or 514:, or 502:, or 319:ASCII 317:like 309:, or 307:digit 248:state 88:SDRAM 5165:PRAM 5160:NRAM 5155:MRAM 5129:PROM 5099:RRAM 5028:SRAM 5015:DRAM 4867:HDMI 4783:SMPS 4771:SSHD 4765:NVMe 4761:SATA 4740:BIOS 4318:PMID 4275:2017 4249:2017 4219:2017 4188:2011 4121:PMID 3995:2011 3965:2011 3939:2011 3913:2011 3883:2011 3817:2019 3791:2019 3769:2019 3697:2011 3671:2011 3641:2008 3614:2008 3542:2007 3510:2015 3479:2011 3434:ISBN 3401:ISBN 3381:2011 3321:OCLC 3311:ISBN 2938:and 2861:RAID 2830:RAID 2828:and 2468:BD-R 2456:CD-R 2297:WORM 2250:CD-i 2244:CD-R 2136:BD-R 1970:MRAM 1946:CRAM 1934:MICR 1910:Drum 1904:Tape 1898:Wire 1839:and 1804:and 1619:and 1534:bits 1435:and 1408:and 1396:CD-R 1394:and 1377:and 1277:Low 1257:Low 1254:Low 1145:Yes 1142:Yes 1139:Yes 1136:Yes 1045:DDR2 983:MAID 943:and 905:and 889:and 855:and 808:and 731:and 723:and 684:BIOS 617:word 597:and 492:drum 441:DRAM 363:For 323:JPEG 284:data 276:byte 272:bits 264:data 197:and 178:The 130:SDLT 111:PATA 5134:ROM 4919:VGA 4914:DVI 4847:USB 4800:VRM 4757:SSD 4752:HDD 4735:RAM 4671:DVD 4534:GPU 4377:doi 4373:100 4310:doi 4298:355 4111:PMC 4103:doi 2985:or 2973:or 2936:NFS 2882:n=2 2874:n=6 2872:or 2870:n=5 2866:n=2 2802:DNA 2766:or 2660:or 2586:on 2446:DVD 2333:UMD 2321:UDO 2185:DVD 2174:PDD 1621:sar 1536:or 1379:SSD 1346:An 1148:No 1128:No 1122:No 1119:No 1116:No 1048:RAM 926:or 891:SSD 887:ODD 883:HDD 810:DVD 773:or 752:RAM 740:ROM 704:). 455:or 449:CPU 329:). 193:'s 159:or 86:of 84:GiB 49:be 5222:: 5101:( 4763:/ 4666:CD 4371:. 4365:. 4324:. 4316:. 4308:. 4296:. 4292:. 4239:. 4235:. 4209:. 4205:. 4174:. 4156:. 4119:. 4109:. 4101:. 4093:. 4079:. 4075:. 4063:^ 4035:. 3981:. 3899:. 3869:. 3851:. 3833:. 3705:^ 3687:. 3657:. 3631:. 3604:. 3581:. 3496:. 3466:. 3442:. 3367:. 3319:. 3309:. 3305:: 3283:^ 3266:. 2977:. 2687:A 2517:, 2488:, 2484:, 2480:, 2476:, 2466:, 2462:, 2458:, 2448:, 2444:, 2440:, 2438:CD 2056:, 2052:, 2010:; 1812:. 1686:. 1655:, 1544:). 1431:, 1232:) 1220:— 1212:— 947:. 885:, 836:. 828:, 824:, 820:, 816:, 806:CD 758:. 746:, 742:, 735:. 562:, 539:, 518:. 510:, 498:, 494:, 490:, 486:, 482:, 463:, 401:, 305:, 230:, 127:GB 108:GB 5105:) 4983:e 4976:t 4969:v 4767:) 4759:( 4419:e 4412:t 4405:v 4385:. 4379:: 4332:. 4312:: 4304:: 4277:. 4251:. 4221:. 4190:. 4160:. 4127:. 4105:: 4097:: 4087:: 4081:7 4039:. 3997:. 3967:. 3941:. 3915:. 3885:. 3855:. 3819:. 3793:. 3771:. 3699:. 3673:. 3643:. 3616:. 3550:. 3544:. 3512:. 3481:. 3409:. 3383:. 3353:. 3327:. 2858:( 2561:e 2554:t 2547:v 2110:e 2103:t 2096:v 2064:; 1878:e 1871:t 1864:v 1611:. 1519:. 1412:. 1398:. 1381:. 451:( 98:. 75:. 57:) 20:)

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