Lexar International is a brand of flash memory products, formerly American-owned, now manufactured by the Chinese memory company, Longsys .
57-590: The Lexar "JumpDrive" trademark was often used synonymously with the term USB flash drives when the technology was first adopted. Lexar was founded as an American manufacturer of digital media products based in San Jose, California . Products manufactured by Lexar include SD cards , CompactFlash cards, USB flash drives , card readers and solid-state drives . Once a division of Cirrus Logic , Lexar leveraged its parent company's experience in building ATA controllers in developing its own flash controllers . Lexar
114-404: A USB floppy drive key , an ordinary USB flash drive with the capacity to emulate floppy drives, allowing it to be used for updating system firmware where direct use of USB flash drives is not supported. The desired mode of operation, regular USB mass storage device or floppy drive emulation, is selected via sliding a switch on the device's housing. Most current PC firmware permits booting from
171-536: A micro USB plug, facilitating data transfers between different devices. Inside the casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs). Typically, one of these ICs provides an interface between the USB connector and the onboard memory, while the other is the flash memory . Drives typically use the USB mass storage device class to communicate with
228-453: A 1 TB USB-C flash drive, the smallest of its kind. [REDACTED] Internals of a typical USB flash drive On a USB flash drive, one end of the device is fitted with a single Standard-A USB plug ; some flash drives additionally offer a micro USB or USB-C plug, facilitating data transfers between different devices. On a USB flash drive, one end of the device is fitted with a single USB plug ; some flash drives additionally offer
285-493: A 2 GB drive being marketed as a 64 GB drive). When plugged into a computer, they report being the larger capacity they were sold as, but when data is written to them, either the write fails, the drive freezes up, or it overwrites existing data. Software tools exist to check and detect fake USB drives, and in some cases it is possible to repair these devices to remove the false capacity information and use its real storage limit. Transfer speeds are technically determined by
342-408: A USB drive, allowing the launch of an operating system from a bootable flash drive. Such a configuration is known as a Live USB . Original flash memory designs had very limited estimated lifetimes. The failure mechanism for flash memory cells is analogous to a metal fatigue mode; the device fails by refusing to write new data to specific cells that have been subject to many read-write cycles over
399-407: A battery to a standard flash memory control microprocessor so it can also serve as a music playback decoder. Most of these players can also be used as a conventional flash drive, for storing files of any type. There are typically five parts to a flash drive: The typical device may also include: Most USB flash drives weigh less than 30 g (1 oz). While some manufacturers are competing for
456-667: A challenging subject that depends on the SLC / MLC / TLC memory type, size of the flash memory chips, and actual usage pattern. As a result, a USB flash drive can last from a few days to several hundred years. Regardless of the endurance of the memory itself, the USB connector hardware is specified to withstand only around 1,500 insert-removal cycles. Counterfeit USB flash drives are sometimes sold with claims of having higher capacities than they actually possess. These are typically low-capacity USB drives with modified flash memory controller firmware that emulates larger capacity drives (for example,
513-568: A feature. Furthermore, for installation of Windows XP , using a USB flash drive with a storage limit of at most 2 GB is recommended in order to boot from it. In Windows Vista and later versions, ReadyBoost feature allows flash drives (from 4 GB in case of Windows Vista) to augment operating system memory. Flash drives are used to carry applications that run on the host computer without requiring installation . While any standalone application can in principle be used this way, many programs store data, configuration information, etc. on
570-447: A few very large ones, and mixed reading and writing to the same device. In a typical well-conducted review of a number of high-performance USB 3.0 drives, a drive that could read large files at 68 MB/s and write at 46 MB/s, could only manage 14 MB/s and 0.3 MB/s with many small files. When combining streaming reads and writes the speed of another drive, the drive could read at 92 MB/s and write at 70 MB/s,
627-540: A flash drive can be used to run installation of Windows or Linux from USB, a process that can be automated via the use of tools like the Universal USB Installer or Rufus . However, for installation of Windows 7 and later versions, using USB flash drive with hard disk drive emulation as detected in PC's firmware is recommended in order to boot from it. Transcend is the only manufacturer of USB flash drives containing such
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#1732875988623684-466: A flash drive with 1 TB of storage. The first USB 3.1 type-C flash drives, with read/write speeds of around 530 MB/s, were announced in March 2015. By July 2016, flash drives with 8 to 256 GB capacity were sold more frequently than those with capacities between 512 GB and 1 TB. In 2017, Kingston Technology announced the release of a 2-TB flash drive. In 2018, SanDisk announced
741-445: A lack of moving parts. Additionally, they are less vulnerable to electromagnetic interference than floppy disks, and are unharmed by surface scratches (unlike CDs). However, as with any flash storage, data loss from bit leaking due to prolonged lack of electrical power and the possibility of spontaneous controller failure due to poor manufacturing could make it unsuitable for long-term archiving of data . The ability to retain data
798-417: A modified USB Type A plug which keeps the total thickness of the card to under 4.5 mm. Because of its small size and USB compatibility, a USB FlashCard could, for example, be accessed by either a digital camera or a modern personal computer without the need for a card reader . Lexar has published the specifications for its USB FlashCard form factor on its website in an open and royalty-free format, in
855-415: A number of handheld devices such as smartphones and tablet computers, though the electronically similar SD card is better suited for those devices, due to their standardized form factor, which allows the card to be housed inside a device without protruding. A flash drive consists of a small printed circuit board carrying the circuit elements and a USB connector, insulated electrically and protected inside
912-424: A plastic, metal, or rubberized case, which can be carried in a pocket or on a key chain, for example. Some are equipped with an I/O indication LED that lights up or blinks upon access. The USB connector may be protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if unprotected. Most flash drives use a standard type-A USB connection allowing connection with
969-464: A port on a personal computer, but drives for other interfaces also exist (e.g. micro-USB and USB-C ports). USB flash drives draw power from the computer via the USB connection. Some devices combine the functionality of a portable media player with USB flash storage; they require a battery only when used to play music on the go. The basis for USB flash drives is flash memory , a type of floating-gate semiconductor memory invented by Fujio Masuoka in
1026-465: A possible inventor of the device. Given these competing inventor claims, patent disputes involving the USB flash drive have arisen over the years. Both Trek 2000 International and Netac Technology have accused others of infringing their patents on the USB flash drive. However, the question of who was the first to invent the USB flash drive has multiple claims persist, the Natec Technology get
1083-506: A prototype 7.5 GB/s PCIe 4.0 SSD which is set to be the world's fastest consumer SSD. In April 2020, Lexar released its world's smallest memory card (nCARD) featuring Xtacking tech from Yangtze Memory Technology (YMTC). In June 2020, Lexar announced its entry to the DRAM market by unveiling seven different DDR4-2666 memory kits for mainstream laptops and desktops. Lexar also plans to release faster, 3000 MHz and 3200 MHz memory kits in
1140-439: Is a data storage device that includes flash memory with an integrated USB interface. A typical USB drive is removable, rewritable, and smaller than an optical disc , and usually weighs less than 30 g (1 oz). Since first offered for sale in late 2000, the storage capacities of USB drives range from 8 megabytes to 256 gigabytes (GB ), 512 GB and 1 terabyte (TB ). As of 2023, 2 TB flash drives were
1197-417: Is affected by the controller's firmware , internal data redundancy , and error correction algorithms. Until about 2005, most desktop and laptop computers were supplied with floppy disk drives in addition to USB ports, but floppy disk drives became obsolete after widespread adoption of USB ports and the larger USB drive capacity compared to the " 1.44 megabyte " 3.5-inch floppy disk. USB flash drives use
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#17328759886231254-401: Is also often used, which has up to 500 write cycles per physical sector, while some high-end flash drives have single-level cell (SLC) based memory that is good for around 30,000 writes. There is virtually no limit to the number of reads from such flash memory, so a well-worn USB drive may be write-protected to help ensure the life of individual cells. Estimation of flash memory endurance is
1311-452: Is downloaded and placed onto a FAT16 - or FAT32 -formatted USB flash drive connected to a system which is to be updated, and the path to the new firmware image is selected within the update component of system's firmware. Some motherboard manufacturers also allow such updates without the need to enter the system's firmware update component, making it possible to easily recover systems with corrupted firmware. In addition, HP has introduced
1368-464: Is equal to one gigabyte (1 GB), where 1 GB is one billion bytes. Randomly addressable semiconductor memory doubles in size for each address lane added to an integrated circuit package, which favors counts that are powers of two. The capacity of a disk drive is the product of the sector size, number of sectors per track, number of tracks per side, and the number of disk platters in the drive. Changes in any of these factors would not usually double
1425-484: Is not necessarily helpful to install one of these file systems. Sectors are 512 bytes long, for compatibility with hard disk drives, and the first sector can contain a master boot record and a partition table . Therefore, USB flash units can be partitioned just like hard disk drives. The memory in flash drives was commonly engineered with multi-level cell (MLC) based memory that is good for around 3,000-5,000 program-erase cycles. Nowadays Triple-level Cell (TLC)
1482-412: Is required not to alter in any way the information stored on the computer being examined. Other forensic suites run from CD-ROM or DVD-ROM , but cannot store data on the media they are run from (although they can write to other attached devices, such as external drives or memory sticks ). Motherboard firmware (including BIOS and UEFI ) can be updated using USB flash drives. Usually, new firmware
1539-546: Is supported in Windows 7 and Windows Vista (Service Pack 2 with a hotfix). A recent development for the use of a USB Flash Drive as an application carrier is to carry the Computer Online Forensic Evidence Extractor (COFEE) application developed by Microsoft . COFEE is a set of applications designed to search for and extract digital evidence on computers confiscated from suspects. Forensic software
1596-521: The FAT32 , or exFAT file systems . The ubiquity of the FAT32 file system allows the drive to be accessed on virtually any host device with USB support. Also, standard FAT maintenance utilities (e.g., ScanDisk ) can be used to repair or retrieve corrupted data . However, because a flash drive appears as a USB-connected hard drive to the host system, the drive can be reformatted to any file system supported by
1653-517: The USB mass storage device class standard, supported natively by modern operating systems such as Windows , Linux , macOS and other Unix-like systems, as well as many BIOS boot ROMs. USB drives with USB 2.0 support can store more data and transfer faster than much larger optical disc drives like CD-RW or DVD-RW drives and can be read by many other systems such as the Xbox One , PlayStation 4 , DVD players, automobile entertainment systems, and in
1710-713: The USB logo only if sold with a separate extension cable. Such cables are USB-compatible but do not conform to the USB standard. USB flash drives have been integrated into other commonly carried items, such as watches, pens, laser pointers, and even the Swiss Army Knife ; others have been fitted with novelty cases such as toy cars or Lego bricks. USB flash drives with images of dragons, cats or aliens are very popular in Asia. The small size, robustness and cheapness of USB flash drives make them an increasingly popular peripheral for case modding . Most flash drives ship preformatted with
1767-623: The basic copyright of American in Dec 7, 2004. And in the lawsuit, the PNY company paid 1,000 million dollars to Natec. Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second (MB/s), megabits per second (Mbit/s), or in optical drive multipliers such as "180X" (180 times 150 KiB /s). File transfer rates vary considerably among devices. Second generation flash drives have claimed to read at up to 30 MB/s and write at about half that rate, which
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1824-643: The binary multiple. In 1999, the International Electrotechnical Commission (IEC) published standards for binary prefixes requiring the use of megabyte to denote 1000 bytes, and mebibyte to denote 1024 bytes. By the end of 2009, the IEC Standard had been adopted by the IEEE , EU , ISO and NIST . Nevertheless, the term megabyte continues to be widely used with different meanings. In this convention, one thousand megabytes (1000 MB)
1881-573: The brand) announced it was to discontinue the Lexar retail removable media storage business and put part or all of the business up for sale. On August 31, 2017, the Lexar brand and trademark rights were acquired by Longsys , a flash memory company based in Shenzhen , China. In 2018, Lexar reentered the flash storage market. In January 2019, the company unveiled the first SD card with a storage capacity of 1 terabyte (TB). In December 2019, Lexar demonstrated
1938-426: The clustered data), and the additional wear on flash drives may not be significant. Some file systems are designed to distribute usage over an entire memory device without concentrating usage on any part (e.g., for a directory) to prolong the life of simple flash memory devices. Some USB flash drives have this ' wear leveling ' feature built into the software controller to prolong device life, while others do not, so it
1995-437: The computer and information technology fields, other definitions have been used that arose for historical reasons of convenience. A common usage has been to designate one megabyte as 1 048 576 bytes (2 B), a quantity that conveniently expresses the binary architecture of digital computer memory. Standards bodies have deprecated this binary usage of the mega- prefix in favor of a new set of binary prefixes , by means of which
2052-687: The device more attractive for more applications. By reducing the probability of the device's premature failure, flash memory devices can now be considered for use where a magnetic disk would normally have been required. Flash drives have also experienced an exponential growth in their storage capacity over time (following the Moore's Law growth curve). As of 2013, single-packaged devices with capacities of 1 TB are readily available, and devices with 16 GB capacity are very economical. Storage capacities in this range have traditionally been considered to offer adequate space, because they allow enough space for both
2109-488: The device's lifetime. Premature failure of a "live USB" could be circumvented by using a flash drive with a write-lock switch as a WORM device , identical to a live CD . Originally, this potential failure mode limited the use of "live USB" system to special-purpose applications or temporary tasks, such as: As of 2011 , newer flash memory designs have much higher estimated lifetimes. Several manufacturers are now offering warranties of 5 years or more. Such warranties should make
2166-481: The early 1980s. Flash memory uses floating-gate MOSFET transistors as memory cells . Multiple individuals have staked a claim to having invented the USB flash drive. On April 5, 1999, Amir Ban , Dov Moran , and Oron Ogdan of M-Systems , an Israeli company, filed a patent application entitled "Architecture for a Universal Serial Bus-Based PC Flash Disk". The patent was subsequently granted on November 14, 2000 and these individuals have often been recognized as
2223-405: The entire contents of the chip. Hardware designers later developed EEPROMs with the erasure region broken up into smaller "fields" that could be erased individually without affecting the others. Altering the contents of a particular memory location involved copying the entire field into an off-chip buffer memory, erasing the field, modifying the data as required in the buffer, and re-writing it into
2280-417: The future, along with kits "with heatsinks and RGB lighting", targeting gamers and enthusiasts. USB FlashCard is a flash memory card format developed by Lexar, and announced on December 13, 2004. There is a wide range of existing memory card formats such as SD , xD , and CompactFlash ; the major advantage of USB FlashCard is that the cards are in fact standard USB flash drives . The USB FlashCard uses
2337-506: The hard drive and registry of the host computer. Megabyte The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB . The unit prefix mega is a multiplier of 1 000 000 (10 ) in the International System of Units (SI). Therefore, one megabyte is one million bytes of information. This definition has been incorporated into the International System of Quantities . In
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2394-634: The hopes that other memory card and portable device manufacturers will adopt it. The specifications for the USB FlashCard published by Lexar show its dimensions to be 31.75 mm × 12 mm × 4.5 mm. The volume is comparable to the widely adopted SD cards (32 mm × 24 mm × 2.1 mm). The USB FlashCard has nearly the same length as the SD card, but is half as wide, and approximately twice as thick. USB flash drive A flash drive (also thumb drive , memory stick , and pen drive / pendrive )
2451-419: The host operating system. Flash drives can be defragmented . There is a widespread opinion that defragmenting brings little advantage (as there is no mechanical head that moves from fragment to fragment), and that defragmenting shortens the life of the drive by making many unnecessary writes. However, some sources claim that defragmenting a flash drive can improve performance (mostly due to improved caching of
2508-430: The host. Flash memory combines a number of older technologies, with lower cost, lower power consumption and small size made possible by advances in semiconductor device fabrication technology. The memory storage is based on earlier EPROM and EEPROM technologies. These had limited capacity, were slow for both reading and writing, required complex high-voltage drive circuitry, and could be re-written only after erasing
2565-448: The inventors of the USB flash drive. Also in 1999, Shimon Shmueli , an engineer at IBM, submitted an invention disclosure asserting that he had invented the USB flash drive. A Singaporean company named Trek 2000 International is the first company known to have sold a USB flash drive, and has also maintained that it is the original inventor of the device. Finally Pua Khein-Seng , a Malaysian engineer, has also been recognized by some as
2622-486: The largest currently in production. Some allow up to 100,000 write/erase cycles, depending on the exact type of memory chip used, and are thought to physically last between 10 and 100 years under normal circumstances ( shelf storage time ). Common uses of USB flash drives are for storage, supplementary back-ups , and transferring of computer files . Compared with floppy disks or CDs , they are smaller, faster, have significantly more capacity, and are more durable due to
2679-448: The memory chips than parallel access , simplifying the manufacture of multi- gigabyte drives. Computers access modern flash memory systems very much like hard disk drives, where the controller system has full control over where information is actually stored. The actual EEPROM writing and erasure processes are, however, still very similar to the earlier systems described above. Many low-cost MP3 players simply add extra software and
2736-419: The norm as data security needs increase; on-the-fly encryption systems are particularly useful in this regard, as they can transparently encrypt large amounts of data. In some cases, a secure USB drive may use a hardware-based encryption mechanism that uses a hardware module instead of software for strongly encrypting data. IEEE 1667 is an attempt to create a generic authentication platform for USB drives. It
2793-486: The operating system software and some free space for the user's data. Installers of some operating systems can be stored to a flash drive instead of a CD or DVD, including various Linux distributions , Windows 7 and newer versions, and macOS . In particular, Mac OS X 10.7 is distributed only online, through the Mac App Store , or on flash drives; for a MacBook Air with Boot Camp and no external optical drive,
2850-461: The protocol overhead that translates to a 35 MB /s effective throughput. That same year, Intel sparked widespread use of second generation USB by including them within its laptops. By 2010, the maximum available storage capacity for the devices had reached upwards of 128 GB. USB 3.0 was slow to appear in laptops. Through 2010, the majority of laptop models still contained only USB 2.0. In January 2013, tech company Kingston, released
2907-471: The quantity 2 B is named mebibyte (symbol MiB). The unit megabyte is commonly used for 1000 (one million) bytes or 1024 bytes. The interpretation of using base 1024 originated as technical jargon for the byte multiples that needed to be expressed by the powers of 2 but lacked a convenient name. As 1024 (2 ) approximates 1000 (10 ), roughly corresponding to the SI prefix kilo- , it was a convenient term to denote
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#17328759886232964-572: The same field. This required considerable computer support, and PC-based EEPROM flash memory systems often carried their own dedicated microprocessor system. Flash drives are more or less a miniaturized version of this. The development of high-speed serial data interfaces such as USB made semiconductor memory systems with serially accessed storage viable, and the simultaneous development of small, high-speed, low-power microprocessor systems allowed this to be incorporated into extremely compact systems. Serial access requires far fewer electrical connections for
3021-578: The slowest of three factors: the USB version used, the speed in which the USB controller device can read and write data onto the flash memory, and the speed of the hardware bus , especially in the case of add-on USB ports. USB flash drives usually specify their read and write speeds in megabytes per second (MB/s); read speed is usually faster. These speeds are for optimal conditions; real-world speeds are usually slower. In particular, circumstances that often lead to speeds much lower than advertised are transfer (particularly writing) of many small files rather than
3078-445: The smallest size, with the biggest memory, offering drives only a few millimeters larger than the USB plug itself, some manufacturers differentiate their products by using elaborate housings, which are often bulky and make the drive difficult to connect to the USB port. Because the USB port connectors on a computer housing are often closely spaced, plugging a flash drive into a USB port may block an adjacent port. Such devices may carry
3135-601: Was 8 MB/s. These differences differ radically from one drive to another; some could write small files 10% faster than for large ones. The examples given are chosen to illustrate extremes. The most common use of flash drives is to transport and store personal files, such as documents, pictures and videos. Individuals also store medical information on flash drives for emergencies and disaster preparation. With wide deployment of flash drives in various environments (secured or otherwise), data and information security remain critical issues. Biometrics and encryption are becoming
3192-424: Was about 20 times faster than the theoretical transfer rate achievable by the previous model, USB 1.1, which is limited to 12 Mbit/s (1.5 MB/s) with accounted overhead. The effective transfer rate of a device is significantly affected by the data access pattern. By 2002, USB flash drives had USB 2.0 connectivity, which has 480 Mbit /s as the transfer rate upper bound; after accounting for
3249-559: Was spun off from Cirrus Logic in 1996. Lexar was created by Petro Estakhri and Mike Assar. In 2005, Lexar was awarded $ 380 million in a lawsuit against Toshiba who copied Lexar's flash memory technology. Lexar was acquired by Micron Technology in 2006, and subsequently merged with Crucial Technology under the name Lexar Media, a subsidiary of Micron. In September 2007, Lexar extended its agreement with Eastman Kodak Company to develop and market Kodak -branded flash memory products worldwide. On June 26, 2017, Micron (the then-owner of
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