Editing USB flash drive (section)

==Comparison with other portable storage==
[[File:IBM card storage.NARA.jpg|thumb|[[Punch card]]s at a U.S. Federal records center in 1959. All this data would readily fit on a 4GB flash drive. Click for details.]]

===Tape===
The applications of current [[data tape cartridge]]s hardly overlap those of flash drives: on tape, cost per gigabyte is very low for large volumes, but the individual drives and media are expensive. Media have a very high capacity and very fast transfer speeds, but store data [[sequential access|sequentially]] and are very slow for random access of data. While disk-based backup is now the primary medium of choice for most companies, tape backup is still popular for taking data off-site for worst-case scenarios and for very large volumes (more than a few hundreds of TB). See [[Linear Tape-Open|LTO]] tapes.

===Floppy disk===
[[File:Flash Drive v. Floppy.jpg|thumb|A flash drive and a 3.5-inch floppy disk. The flash drive can hold approximately 11,380 times more data.]]
[[Floppy disk]] drives are rarely fitted to modern computers and are obsolete for normal purposes, although internal and external drives can be fitted if required. Floppy disks may be the method of choice for transferring data to and from very old computers without USB or [[booting]] from floppy disks, and so they are sometimes used to change the firmware on, for example, [[BIOS]] chips. Devices with removable storage like older [[Yamaha Corporation|Yamaha]] music keyboards are also dependent on floppy disks, which require computers to process them. Newer devices are built with USB flash drive support.

[[Floppy disk hardware emulator]]s exist which effectively utilize the internal connections and physical attributes of a floppy disk drive to utilize a device where a USB flash drive emulates the storage space of a floppy disk in a solid state form, and can be divided into a number of individual virtual floppy [[disk image]]s using individual data channels.

===Optical media===
The various writable and re-writable forms of [[CD]] and [[DVD]] are portable storage media supported by the vast majority of computers as of 2008. CD-R, DVD-R, and DVD+R can be written to only once, RW varieties up to about 1,000 erase/write cycles, while modern NAND-based flash drives often last for 500,000 or more erase/write cycles. [[DVD-RAM]] discs are the most suitable optical discs for data storage involving much rewriting.

[[Optical storage device]]s are among the cheapest methods of mass data storage after the hard drive. They are slower than their flash-based counterparts. Standard 120&nbsp;mm optical discs are larger than flash drives and more subject to damage. Smaller optical media do exist, such as [[business card CD]]-Rs which have the same dimensions as a credit card, and the slightly less convenient but higher capacity 80&nbsp;mm recordable [[MiniCD]] and [[Mini DVD]]. The small discs are more expensive than the standard size, and do not work in all drives.

[[Universal Disk Format]] (UDF) version 1.50 and above has facilities to support rewritable discs like sparing tables and virtual [[File Allocation Table|allocation tables]], spreading usage over the entire surface of a disc and maximising life, but many older operating systems do not support this format. Packet-writing utilities such as DirectCD and [[InCD]] are available but produce discs that are not universally readable (although based on the [[Universal Disk Format|UDF]] standard). The [[Mount Rainier (packet writing)|Mount Rainier]] standard addresses this shortcoming in CD-RW media by running the older file systems on top of it and performing defect management for those standards, but it requires support from both the CD/DVD burner and the [[operating system]]. Many drives made today do not support Mount Rainier, and many older operating systems such as Windows XP and below, and Linux kernels older than 2.6.2, do not support it (later versions do). Essentially CDs/DVDs are a good way to record a great deal of information cheaply and have the advantage of being readable by most standalone players, but they are poor at making ongoing small changes to a large collection of information. Flash drives' ability to do this is their major advantage over optical media.

===Flash memory cards===
[[File:8GB media comparison.jpg|thumb|Three different [[Micro Center]]-branded digital media, showing a USB flash drive, an [[SD card]], and a Micro-SD card, all having a capacity of 8&nbsp;GiB, next to a U.S. 5-cent coin for size comparison]]
[[Flash memory card]]s, e.g., [[Secure Digital card]]s, are available in various formats and capacities, and are used by many consumer devices. However, while virtually all PCs have USB ports, allowing the use of USB flash drives, memory card readers are not commonly supplied as standard equipment (particularly with desktop computers). Although inexpensive card readers are available that read many common formats, this results in two pieces of portable equipment (card plus reader) rather than one.

Some manufacturers, aiming at a "best of both worlds" solution, have produced card readers that approach the size and form of USB flash drives (e.g., [[Kingston Technology|Kingston]] MobileLite,<ref>{{cite web|url=http://www.kingston.com/flash/mobilelite_reader.asp|title=MobileLite 9-in-1 Reader|publisher=[[Kingston Technology]]|access-date=2009-04-08|url-status=dead|archive-url=https://web.archive.org/web/20090227044548/http://kingston.com/flash/mobilelite_reader.asp|archive-date=2009-02-27}}</ref> [[SanDisk]] MobileMate<ref>{{cite web |url=http://www.sandisk.com/Products/Item(1219)-SDDR-108-A11M-SanDisk_MobileMate_Memory_Stick_Plus_4in1_Reader.aspx |title=MobileMate Memory Stick Plus 4-in-1 Reader |publisher=[[SanDisk|Sandisk Corporation]] |access-date=2009-04-08 |url-status=dead |archive-url=https://web.archive.org/web/20090305041708/http://www.sandisk.com/Products/Item%281219%29-SDDR-108-A11M-SanDisk_MobileMate_Memory_Stick_Plus_4in1_Reader.aspx |archive-date=March 5, 2009 }}</ref>) These readers are limited to a specific subset of memory card formats (such as SD, [[SD card#microSD|microSD]], or [[Memory Stick]]), and often completely enclose the card, offering durability and portability approaching, if not quite equal to, that of a flash drive. Although the combined cost of a mini-reader and a memory card is usually slightly higher than a USB flash drive of comparable capacity, the reader + card solution offers additional flexibility of use, and virtually "unlimited" capacity. The ubiquity of [[SD cards]] is such that, circa 2011, due to [[economies of scale]], their price is now less than an equivalent-capacity USB flash drive, even with the added cost of a USB SD card reader.

An additional advantage of memory cards is that many consumer devices (e.g., [[digital camera]]s, [[portable music player]]s) cannot make use of USB flash drives (even if the device has a USB port), whereas the memory cards used by the devices can be read by PCs with a card reader.

===External hard disk===
Particularly with the advent of USB, [[External hard disk drive|external hard disks]] have become widely available and inexpensive. External hard disk drives currently cost less per gigabyte than flash drives and are available in larger capacities. Some hard drives support alternative and faster interfaces than USB 2.0 (e.g., [[Thunderbolt (interface)|Thunderbolt]], [[IEEE 1394|FireWire]] and [[eSATA]]). For consecutive sector writes and reads (for example, from an unfragmented file), most hard drives can provide a much higher sustained data rate than current NAND flash memory, though [[Latency (engineering)#Mechanical latency|mechanical latencies]] seriously impact hard drive performance.

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 shielded by their casings, 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 (computer)|fragmentation]], which can reduce access speed{{Citation needed|date=January 2022}}.

===External solid-state drive===
Compared to external [[solid-state drive]]s, USB flash drives are usually built using lower-cost and lower-performance [[flash memory]], resulting in lower overall performance.

===Obsolete devices===
[[Compact cassette|Audio tape cassettes]] and high-capacity floppy disks (e.g., [[Imation]] [[SuperDisk]]), and other forms of drives with removable magnetic media, such as the Iomega [[Zip drive]] and [[Jaz drive]]s, are now largely obsolete and rarely used. There are products in today's market that will emulate these legacy drives for both tape and disk (SCSI1/SCSI2, SASI, Magneto optic, Ricoh ZIP, Jaz, IBM3590/ Fujitsu 3490E and Bernoulli for example) in state-of-the-art Compact Flash storage devices – CF2SCSI.

===Encryption and security===
{{main|USB flash drive security}}

As highly portable media, USB flash drives are easily lost or stolen. All USB flash drives can have their contents encrypted using third-party disk encryption software, which can often be run directly from the USB drive without installation (for example, [[FreeOTFE]]), although some, such as BitLocker, require the user to have administrative rights on every computer it is run on.

Archiving software can achieve a similar result by creating encrypted [[ZIP (file format)|ZIP]] or [[RAR (file format)|RAR]] files.<ref>{{cite web|url=https://www.pkware.com/software/pkzip/server/technical-specs|title=Technical Specifications - PKZIP Server - PKWARE - server - pkzip - software|author=Arlen Walker|work=pkware.com|access-date=29 June 2015|archive-date=18 October 2015|archive-url=https://web.archive.org/web/20151018213413/https://www.pkware.com/software/pkzip/server/technical-specs|url-status=live}}</ref><ref>{{cite web|url=http://www.rarlab.com/rar_archiver.htm|title=WinRAR archiver, a powerful tool to process RAR and ZIP files|work=rarlab.com|access-date=29 June 2015|archive-date=3 July 2015|archive-url=https://web.archive.org/web/20150703053034/http://www.rarlab.com/rar_archiver.htm|url-status=live}}</ref>

Some manufacturers have produced USB flash drives which use hardware-based encryption as part of the design,<ref name=hardware_encryption>{{cite web |url=http://www.goldkey.com/products/secure-encrypted-flash-drive.html |title=Encrypted & Secure USB Flash Drive - GoldKey |access-date=2016-02-09 |url-status=dead |archive-url=https://archive.today/20130124123810/http://www.goldkey.com/products/secure-encrypted-flash-drive.html |archive-date=2013-01-24 }}</ref> removing the need for third-party encryption software. In limited circumstances these drives have been [[USB flash drive security#Compromised systems|shown to have security problems]], and are typically more expensive than software-based systems, which are available for free.

A minority of flash drives support [[biometric]] [[fingerprinting]] to confirm the user's identity. As of mid-{{As of|2005|alt=2005}},{{Update after|2010|11|13}} 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.<ref>{{cite web|url=http://www.heise-online.co.uk/security/Secure-USB-sticks-cracked--/features/110280|title=heise online - IT-News, Nachrichten und Hintergründe|work=heise online|access-date=2008-03-21|archive-date=2008-12-26|archive-url=https://web.archive.org/web/20081226053259/http://www.heise-online.co.uk/security/Secure-USB-sticks-cracked--/features/110280|url-status=live}}</ref>

Some manufacturers deploy [[Dongle|physical authentication tokens]] in the form of a flash drive. These are used to control access to a sensitive system by containing encryption keys or, more commonly, communicating with security software on the target machine. The system is designed so the target machine will not operate except when the flash drive device is plugged into it. Some of these "PC lock" devices also function as normal flash drives when plugged into other machines.