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48-414: The Data Discman was designed to allow quick access to electronic reference information on a pre-recorded disc . Searching terms were entered using a QWERTY -style keyboard and utilized the "Yes" and "No" keys. A typical Data Discman model has a low resolution small grayscale LCD (256x200 early on, later models would have up to 320x240 and in colour), CD drive unit (either Mini CD or full size), and

96-475: A Samsung 970 EVO NVMe M.2 SSD (2018) with 1 TB of capacity has an endurance rating of 600 TBW. Recovering data from SSDs presents challenges due to the non-linear and complex nature of data storage in solid-state drives. The internal operations of SSDs vary by manufacturer, with commands (e.g. TRIM and the ATA Secure Erase) and programs like (e.g. hdparm ) being able to erase and modify

144-428: A cache (configurable as write-through or write-back ) for a conventional, magnetic hard disk drive. A similar technology is available on HighPoint 's RocketHybrid PCIe card. Solid-state hybrid drives (SSHDs) are based on the same principle, but integrate some amount of flash memory on board of a conventional drive instead of using a separate SSD. The flash layer in these drives can be accessed independently from

192-409: A live SD operating system are easily write-locked . Combined with a cloud computing environment or other writable medium, an OS booted from a write-locked SD card is reliable, persistent and impervious to permanent corruption. In 2011, Intel introduced a caching mechanism for their Z68 chipset (and mobile derivatives) called Smart Response Technology , which allows a SATA SSD to be used as

240-569: A PCIe card available in the second half of 2017. Despite the initial lukewarm reception when first released, 3D XPoint – particularly in the form of Intel's Optane range – has been highly acclaimed and widely recommended for tasks where its specific features are of value, with reviewers such as Storage Review concluding in August 2018 that for low-latency workloads, 3D XPoint was producing 500,000 4K sustained IOPS for both reads and writes, with 3–15 microsecond latencies, and that at present "there

288-457: A caching or acceleration disk, and it is also fast enough to be used as non-volatile RAM (NVRAM) or persistent memory in a DIMM package. Development of 3D XPoint began around 2012. Intel and Micron had developed other non-volatile phase-change memory (PCM) technologies previously; Mark Durcan of Micron said 3D XPoint architecture differs from previous offerings of PCM, and uses chalcogenide materials for both selector and storage parts of

336-411: A constant power supply to retain data. DRAM-based SSDs are typically used in specialized applications where performance is prioritized over cost or non-volatility. Many SSDs, such as NVDIMM devices, are equipped with backup power sources such as internal batteries or external AC/DC adapters. These power sources ensure data is transferred to a backup system (usually NAND flash or another storage medium) in

384-471: A constant power supply. NAND flash-based SSDs store data in semiconductor cells, with the specific architecture influencing performance, endurance, and cost. There are various types of NAND flash memory, categorized by the number of bits stored in each cell: Over time, SSD controllers have improved the efficiency of NAND flash, incorporating techniques such as interleaved memory , advanced error correction, and wear leveling to optimize performance and extend

432-807: A controller, which manages the data flow between the NAND memory and the host computer. The controller is an embedded processor that runs firmware to optimize performance, managing data, and ensuring data integrity. Some of the primary functions performed by the controller are: The overall performance of an SSD can scale with the number of parallel NAND chips and the efficiency of the controller. For example, controllers that enable parallel processing of NAND flash chips can improve bandwidth and reduce latency. Micron and Intel pioneered faster SSDs by implementing techniques such as data striping and interleaving to enhance read/write speeds. More recently, SandForce introduced controllers that incorporate data compression to reduce

480-743: A limited lifetime number of writes, and also slow down as they reach their full storage capacity. SSDs also have internal parallelism that allows them to manage multiple operations simultaneously, which enhances their performance. Unlike HDDs and similar electromechanical magnetic storage , SSDs do not have moving mechanical parts, which provides advantages such as resistance to physical shock, quieter operation, and faster access times. Their lower latency results in higher input/output rates (IOPS) than HDDs. Some SSDs are combined with traditional hard drives in hybrid configurations, such as Intel's Hystor and Apple's Fusion Drive . These drives use both flash memory and spinning magnetic disks in order to improve

528-666: A low-power computer. Early versions of the device were incapable of playing audio CDs . Software was prerecorded and usually featured encyclopedias, foreign language dictionaries and novels. It was typically created using the Sony Electronic Book Authoring System (SEBAS). A DD-1EX Data Discman is in the permanent collection of the Victoria and Albert Museum and is currently displayed in the V&;A's 20th Century Gallery. This early model did not include

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576-864: A lower cost than pure SSDs. An SSD stores data in semiconductor cells, with its properties varying according to the number of bits stored in each cell (between 1 and 4). Single-level cells (SLC) store one bit of data per cell and provide higher performance and endurance. In contrast, multi-level cells (MLC), triple-level cells (TLC), and quad-level cells (QLC) store more data per cell but have lower performance and endurance. SSDs using 3D XPoint technology, such as Intel’s Optane, store data by changing electrical resistance instead of storing electrical charges in cells, which can provide faster speeds and longer data persistence compared to conventional flash memory. SSDs based on NAND flash slowly leak charge when not powered, while heavily-used consumer drives may start losing data typically after one to two year in storage. SSDs have

624-484: A memory component, Optane requires specific chipset and CPU support. As an ordinary SSD, Optane is broadly compatible with a very wide range of systems, and its main requirements are much like any other SSD – ability to be plugged into the hardware, operating system, BIOS/UEFI and driver support for NVMe, and adequate cooling. Micron offered NVMe AIC SSD drives (QuantX X100 ) which maintained compatibility with NVMe capable systems. Native support as an acceleration device

672-623: A non-volatile memory, 3D XPoint has a number of features that distinguish it from other currently available RAM and NVRAM . Although the first generations of 3D XPoint were not especially large or fast, 3D XPoint was used to create some of the fastest SSDs available as of 2019, with small-write latency . As the memory is inherently fast, and byte-addressable, techniques such as read-modify-write and caching used to enhance traditional SSDs are not needed to obtain high performance. In addition, chipsets such as Cascade Lake are designed with inbuilt support for 3D XPoint, which allows it to be used as

720-936: A small amount of volatile DRAM as a cache, similar to the buffers in hard disk drives. This cache can temporarily hold data while it is being written to the flash memory, and it also stores metadata such as the mapping of logical blocks to physical locations on the SSD. Some SSD controllers, like those from SandForce, achieve high performance without using an external DRAM cache. These designs rely on other mechanisms, such as on-chip SRAM, to manage data and minimize power consumption. Additionally, some SSDs use an SLC cache mechanism to temporarily store data in single-level cell (SLC) mode, even on multi-level cell (MLC) or triple-level cell (TLC) SSDs. This improves write performance by allowing data to be written to faster SLC storage before being moved to slower, higher-capacity MLC or TLC storage. On NVMe SSDs, Host Memory Buffer (HMB) technology allows

768-601: A sudden power loss. Some consumer SSDs have built-in capacitors to save critical data such as the Flash Translation Layer (FTL) mapping table. Examples include the Crucial M500 and Intel 320 series. Enterprise-class SSDs, such as the Intel DC S3700 series, often come with more robust power-loss protection mechanisms like supercapacitors or batteries. The host interface of an SSD refers to

816-735: A system in the same way as HDDs, SSDs are used in a variety of devices, including personal computers , enterprise servers , and mobile devices . However, SSDs are generally more expensive on a per-gigabyte basis and have a finite number of write cycles, which can lead to data loss over time. Despite these limitations, SSDs are increasingly replacing HDDs, especially in performance-critical applications and as primary storage in many consumer devices. SSDs come in various form factors and interface types, including SATA , PCIe , and NVMe , each offering different levels of performance. Hybrid storage solutions, such as solid-state hybrid drives (SSHDs), combine SSD and HDD technologies to offer improved performance at

864-580: Is a discontinued non-volatile memory (NVM) technology developed jointly by Intel and Micron Technology . It was announced in July 2015 and was available on the open market under the brand name Optane (Intel) from April 2017 to July 2022. Bit storage is based on a change of bulk resistance , in conjunction with a stackable cross-grid data access array, using a phenomenon known as Ovonic Threshold Switch (OTS). Initial prices are less than dynamic random-access memory (DRAM) but more than flash memory . As

912-537: Is currently nothing [else] that comes close", while Tom's Hardware described the Optane 900p in December 2017 as being like a "mythical creature" that must be seen to be believed, and which doubled the speed of the best previous consumer devices. ServeTheHome concluded in 2017 that in read, write and mixed tests, Optane SSDs were consistently around 2.5× as fast as the best Intel datacentre SSDs which had preceded them,

960-496: Is infrequently changed (cold data) from heavily used blocks, so that data that changes more frequently (hot data) can be written to those blocks. This helps distribute wear more evenly across the entire SSD. However, this process introduces additional writes, known as write amplification, which must be managed to balance performance and durability. Most SSDs use non-volatile NAND flash memory for data storage, primarily due to its cost-effectiveness and ability to retain data without

1008-655: The Optane brand for storage products based on 3D XPoint technology. Micron (using the QuantX brand) estimated the memory to be sold for about half the price of dynamic random-access memory (DRAM), but four to five times the price of flash memory . Initially, a wafer fabrication facility in Lehi, Utah , operated by IM Flash Technologies LLC (an Intel-Micron joint venture) made small quantities of 128 Gbit chips in 2015. They stack two 64 Gbit planes. In early 2016 mass production of

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1056-466: The magnetic storage by the host using ATA-8 commands, allowing the operating system to manage it. For example, Microsoft's ReadyDrive technology explicitly stores portions of the hibernation file in the cache of these drives when the system hibernates, making the subsequent resume faster. Dual-drive hybrid systems are combining the usage of separate SSD and HDD devices installed in the same computer, with overall performance optimization managed by

1104-487: The P3700 NVMe. AnandTech noted that consumer Optane-based SSDs were similar in performance to the best non-3D-XPoint SSDs for large transfers, with both being "blown away" by the large transfer performance of enterprise Optane SSDs. On March 16, 2021, Micron announced that it would cease development of 3D XPoint in order to develop products based on Compute Express Link (CXL), due to a lack of demand. The Lehi fab

1152-508: The SSD to use a portion of the system’s DRAM instead of relying on a built-in DRAM cache, reducing costs while maintaining a high level of performance. In certain high-end consumer and enterprise SSDs, larger amounts of DRAM are included to cache both file table mappings and written data, reducing write amplification and enhances overall performance. Higher-performing SSDs may include a capacitor or battery, which helps preserve data integrity in

1200-680: The ability to play sound. An updated model, the DD-10EX, was released in 1992 or 1993. The accompanying manual gives a copyright date of 1992. Unlike the DD-1EX, the DD-10EX also had the ability to play audio files. The British version came with a disc containing the Thomson Electronic Directory for April 1992, plus another containing the Pocket Interpreter 5-language conversation book for travelers . A DD-10EX

1248-450: The amount of data written to the flash memory, potentially increasing both performance and endurance. Wear leveling is a technique used in SSDs to ensure that write and erase operations are distributed evenly across all blocks of the flash memory. Without this, specific blocks could wear out prematurely due to repeated use, reducing the overall lifespan of the SSD. The process moves data that

1296-418: The bits of a deleted file. The JEDEC Solid State Technology Association (JEDEC) has established standards for SSD reliability metrics, which include: In a distributed computing environment, SSDs can be used as a distributed cache layer that temporarily absorbs the large volume of user requests to slower HDD-based backend storage systems. This layer provides much higher bandwidth and lower latency than

1344-537: The chips was expected in 12 to 18 months. In early 2016, IM Flash announced that the first generation of solid-state drives would achieve 95000 IOPS throughput with 9 microsecond latency. This low latency significantly increases IOPS at low queue depths for random operations. At Intel Developer Forum 2016, Intel demonstrated PCI Express (PCIe) 140 GB development boards showing 2.4–3× improvement in benchmarks compared to PCIe NAND flash solid-state drives (SSDs). On March 19, 2017, Intel announced their first product:

1392-426: The complete loss of the drive. Most of the advantages of solid-state drives over traditional hard drives are due to their ability to access data completely electronically instead of electromechanically, resulting in superior transfer speeds and mechanical ruggedness. On the other hand, hard disk drives offer significantly higher capacity for their price. In traditional HDDs, a rewritten file will generally occupy

1440-691: The computer like hard drives. In contrast, memory cards (such as Secure Digital (SD), CompactFlash (CF), and many others) were originally designed for digital cameras and later found their way into cell phones, gaming devices, GPS units, etc. Most memory cards are physically smaller than SSDs, and designed to be inserted and removed repeatedly. SSDs have different failure modes from traditional magnetic hard drives. Because solid-state drives contain no moving parts, they are generally not subject to mechanical failures. However, other types of failures can occur. For example, incomplete or failed writes due to sudden power loss may be more problematic than with HDDs, and

1488-593: The computer user, or by the computer's operating system software. Examples of this type of system are bcache and dm-cache on Linux , and Apple's Fusion Drive . The primary components of an SSD are the controller and the memory used to store data. Traditionally, early SSDs used volatile DRAM for storage, but since 2009, most SSDs utilize non-volatile NAND flash memory, which retains data even when powered off. Flash memory SSDs store data in metal–oxide–semiconductor (MOS) integrated circuit chips, using non-volatile floating-gate memory cells. Every SSD includes

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1536-423: The data storage material which is accessed by ovonic threshold switches (OTSes) made of ternary phased selenium-germanium-silicon with arsenic doping. 3D XPoint has been the most widely produced standalone memory based on other than charge storage, whereas other alternative memories, like ReRAM or Magnetoresistive RAM , have so far only been widely developed on embedded platforms. In mid-2015, Intel announced

1584-509: The electrical resistance of materials in its cells, offering much faster access times than NAND flash. 3D XPoint-based SSDs, such as Intel’s Optane drives, provide lower latency and higher endurance than NAND-based drives, although they are more expensive per gigabyte. Drives known as hybrid drives or solid-state hybrid drives (SSHDs) use a hybrid of spinning disks and flash memory. Some SSDs use magnetoresistive random-access memory (MRAM) for storing data. Many flash-based SSDs include

1632-535: The event of an unexpected power loss. The capacitor or battery provides enough power to allow the data in the cache to be written to the non-volatile memory, ensuring no data is lost. In some SSDs that use multi-level cell (MLC) flash memory, a potential issue known as "lower page corruption" can occur if power is lost while programming an upper page. This can result in previously written data becoming corrupted. To address this, some high-end SSDs incorporate supercapacitors to ensure all data can be safely written during

1680-493: The event of power loss, preventing data corruption or loss. Similarly, ULLtraDIMM devices use components designed for DIMM modules, but only use flash memory, similar to a DRAM SSD. DRAM-based SSDs are often used for tasks where data must be accessed at high speeds with low latency, such as in high-performance computing or certain server environments. 3D XPoint is a type of non-volatile memory technology developed by Intel and Micron, announced in 2015. It operates by changing

1728-467: The failure of a single chip may result in the loss of all data stored on it. Nonetheless, studies indicate that SSDs are generally reliable, often exceed their manufacturer-stated lifespan and having lower failure rates than HDDs. However, studies also note that SSDs experience higher rates of uncorrectable errors, which can lead to data loss, compared to HDDs. The endurance of an SSD is typically listed on its datasheet in one of two forms: For example,

1776-628: The flat, rectangular design of the DD-8 was closer to later e-book readers such as the Amazon Kindle . Electronic disk A solid-state drive ( SSD ) is a type of solid-state storage device that uses integrated circuits to store data persistently . It is sometimes called semiconductor storage device , solid-state device , or solid-state disk . SSDs rely on non-volatile memory, typically NAND flash , to store data in memory cells. The performance and endurance of SSDs vary depending on

1824-485: The lifespan of the drive. Lower-end SSDs often use QLC or TLC memory, while higher-end drives for enterprise or performance-critical applications may use MLC or SLC. In addition to the flat (planar) NAND structure, many SSDs now use 3D NAND (or V-NAND), where memory cells are stacked vertically, increasing storage density while improving performance and reducing costs. Some SSDs use volatile DRAM instead of NAND flash, offering very high-speed data access but requiring

1872-582: The memory cells. 3D XPoint developers indicate that it is based on changes in resistance of the bulk material. Intel CEO Brian Krzanich responded to ongoing questions on the XPoint material that the switching was based on "bulk material properties". Intel has stated that 3D XPoint does not use a phase-change or memristor technology, although this is disputed by independent reviewers. According to reverse engineering firm TechInsights, 3D XPoint uses germanium-antimony-tellurium (GST) with low silicon content as

1920-549: The memory cell that are faster and more stable than traditional PCM materials like GST . But today, it is thought of as a subset of ReRAM . According to patents a variety of materials can be used as the chalcogenide material. 3D XPoint has been stated to use electrical resistance and to be bit addressable. Similarities to the resistive random-access memory under development by Crossbar Inc. have been noted, but 3D XPoint uses different storage physics. Specifically, transistors are replaced by threshold switches as selectors in

1968-553: The number of bits stored per cell, ranging from high-performing single-level cells (SLC) to more affordable but slower quad-level cells (QLC). In addition to flash-based SSDs, other technologies such as 3D XPoint offer faster speeds and higher endurance through different data storage mechanisms. Unlike traditional hard disk drives (HDDs), SSDs have no moving parts, allowing them to deliver faster data access speeds, reduced latency, increased resistance to physical shock, lower power consumption, and silent operation. Often interfaced to

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2016-741: The performance characteristics such as rotational latency and seek time . As SSDs do not need to spin or seek to locate data, they are vastly superior to HDDs in such tests. However, SSDs have challenges with mixed reads and writes, and their performance may degrade over time. Therefore, SSD testing typically looks at when the full drive is first used, as the new and empty drive may have much better write performance than it would show after only weeks of use. The reliability of both HDDs and SSDs varies greatly among models. Some field failure rates indicate that SSDs are significantly more reliable than HDDs. However, SSDs are sensitive to sudden power interruption, sometimes resulting in aborted writes or even cases of

2064-554: The performance of frequently-accessed data. Traditional interfaces (e.g. SATA and SAS ) and standard HDD form factors allow such SSDs to be used as drop-in replacements for HDDs in computers and other devices. Newer form factors such as mSATA , M.2 , U.2 , NF1 / M.3 / NGSFF , XFM Express ( Crossover Flash Memory , form factor XT2) and EDSFF and higher speed interfaces such as NVM Express (NVMe) over PCI Express (PCIe) can further increase performance over HDD performance. Traditional HDD benchmarks tend to focus on

2112-497: The physical connector and the signaling methods used to communicate between the SSD and the host system. This interface is managed by the SSD's controller and is often similar to those found in traditional hard disk drives (HDDs). Common interfaces include: SSDs may support various logical interfaces, which define the command sets used by operating systems to communicate with the SSD. Two common logical interfaces include: 3D XPoint 3D XPoint (pronounced three-D cross point )

2160-543: The same location on the disk surface as the original file, whereas in SSDs the new copy will often be written to different NAND cells for the purpose of wear leveling . The wear-leveling algorithms are complex and difficult to test exhaustively. As a result, one major cause of data loss in SSDs is firmware bugs. While both memory cards and most SSDs use flash memory, they have very different characteristics, including power consumption, performance, size, and reliability. Originally, solid state drives were shaped and mounted in

2208-638: The storage system would, and can be managed in a number of forms, such as a distributed key-value database and a distributed file system . On supercomputers, this layer is typically referred to as burst buffer . Flash-based solid-state drives can be used to create network appliances from general-purpose personal computer hardware. A write protected flash drive containing the operating system and application software can substitute for larger, less reliable disk drives or CD-ROMs. Appliances built this way can provide an inexpensive alternative to expensive router and firewall hardware. SSDs based on an SD card with

2256-617: Was included in an exhibition entitled The Book and Beyond: Electronic Publishing and the Art of the Book , held at the Victoria and Albert Museum , London, from April to October 1995. The exhibition also included a CD-ROM designed to be played on the Data Discman, entitled Library of the Future and published in 1993. The DD-1EX and DD-10EX both made use of a flip or clamshell form, while

2304-546: Was never fully utilized, and was sold to Texas Instruments for USD 900 million. Intel responded at the time that its ability to supply Intel Optane products would not be affected. However, Intel had already discontinued its consumer line of Optane products in January 2021. In July 2022, Intel announced the winding down of the Optane division, effectively discontinuing the development of 3D XPoint. Intel distinguishes between "Intel Optane Memory" and "Intel Optane SSDs". As

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