“The Samsung BAR is incredibly small and easily portable, measuring just under 2-inches long,” our tester said. He added, “It's also extremely durable: waterproof, shockproof, as well as x-rays and magnets [proof].” The included key ring adds to its portability, according to our reviewer. On the flip side, he called the transfer speeds “decent but mostly unremarkable.” Our tester concluded, “Most of the BAR's problems are due to Samsung releasing a newer, cheaper model, the BAR Plus.”
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, a flash drive can be used to run installation of Windows or Linux.
Some organizations forbid the use of flash drives, and some computers are configured to disable the mounting of USB mass storage devices by users other than administrators; others use third-party software to control USB usage. The use of software allows the administrator to not only provide a USB lock but also control the use of CD-RW, SD cards and other memory devices. This enables companies with policies forbidding the use of USB flash drives in the workplace to enforce these policies. In a lower-tech security solution, some organizations disconnect USB ports inside the computer or fill the USB sockets with epoxy.
Buoyed by its rocket-like speeds, the Extreme Go lives up to its name by transferring a 4K movie in less than 40 seconds — that's nearly 35 times the speed of a USB 2.0 drive and thanks to USB 3.1 hardware. Beyond its fast operation, the Sandisk looks as good as it performs with a sleek and slim package that's 2.79 x 0.84 x 0.45 inches in size and weighs only 4.8 ounces. The retractable connector makes it easy to store when not in use and it is backward compatible with any USB 3.0 or USB 2.0 port. Tucked inside its diminutive profile is a choice of 64GB or 128GB of storage capacity and it comes complete with data storage recovery in the event of an accidental file deletion.
External flash drives use what's known as "solid-state" storage, which can store, back up, and retrieve data using only electronic circuits. Solid-state drives do not contain any moving mechanical parts, which enables them to access data quickly and easy. A typical flash drive allows up to 100,000 write/erase cycles before the integrity of the data starts to degrade. This translates to around a 10-year lifespan, depending on how much it is used.
A drawback to the small size of flash drives is that they are easily misplaced or otherwise lost. This is a particular problem if they contain sensitive data (see data security). As a consequence, some manufacturers have added encryption hardware to their drives, although software encryption systems which can be used in conjunction with any mass storage medium will achieve the same result. Most drives can be attached to keychains or lanyards. The USB plug is usually retractable or fitted with a removable protective cap.
Flash drives are also cost-effective. You can securely store a few dozen gigabytes of data for less than $30, and these devices range in storage capacity, price and overall size - equal to the amount you're willing to invest. Some even have special features like lanyards, locks, belt clips and key fobs to make them easier to carry and keep track of.
A USB flash drive[note 1] is a data storage device that includes flash memory with an integrated USB interface. It is typically removable, rewritable and much smaller than an optical disc. Most weigh less than 30 g (1 oz). Since first appearing on the market in late 2000, as with virtually all other computer memory devices, storage capacities have risen while prices have dropped. As of March 2016, flash drives with anywhere from 8 to 256 GB were frequently sold, while 512 GB and 1 TB units were less frequent.[2][3] As of 2018, 2 TB flash drives were the largest available in terms of storage capacity.[4] Some allow up to 100,000 write/erase cycles, depending on the exact type of memory chip used, and are thought to last between 10 and 100 years under normal circumstances (shelf storage time[5]).
Flash drives implement the USB mass storage device class so that most modern operating systems can read and write to them without installing device drivers. The flash drives present a simple block-structured logical unit to the host operating system, hiding the individual complex implementation details of the various underlying flash memory devices. The operating system can use any file system or block addressing scheme. Some computers can boot up from flash drives.
A minority of flash drives support biometric fingerprinting to confirm the user's identity. As of mid-2005,[needs update] this was an expensive alternative to standard password protection offered on many new USB flash storage devices. Most fingerprint scanning drives rely upon the host operating system to validate the fingerprint via a software driver, often restricting the drive to Microsoft Windows computers. However, there are USB drives with fingerprint scanners which use controllers that allow access to protected data without any authentication.[70]
Lexar is attempting to introduce a USB FlashCard, which would be a compact USB flash drive intended to replace various kinds of flash memory cards. Pretec introduced a similar card, which also plugs into any USB port, but is just one quarter the thickness of the Lexar model.[85] Until 2008, SanDisk manufactured a product called SD Plus, which was a SecureDigital card with a USB connector.[86]
USB flash drives have been integrated into other commonly carried items, such as watches, pens, 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.[36] The small size, robustness and cheapness of USB flash drives make them an increasingly popular peripheral for case modding.
Unlike solid-state memory, hard drives are susceptible to damage by shock (e.g., a short fall) and vibration, have limitations on use at high altitude, and although they are shielded by their casings, they are vulnerable when exposed to strong magnetic fields. In terms of overall mass, hard drives are usually larger and heavier than flash drives; however, hard disks sometimes weigh less per unit of storage. Like flash drives, hard disks also suffer from file fragmentation, which can reduce access speed.
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 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.
