Editing USB flash drive (section)

===Technology improvements===
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&nbsp;[[Kibibyte|KiB]]/s).<ref>{{cite web|url=http://vampiric.us/index.php/articles/hardware/optical/opticalthroughpm|title=4 Optical Drives through Port Multiplier|website=vampiric.us|archive-url=https://web.archive.org/web/20141228185855/http://vampiric.us/index.php/articles/hardware/optical/opticalthroughpm|archive-date=28 December 2014|url-status=dead|access-date=22 December 2014|df=dmy-all}}</ref> File transfer rates vary considerably among devices. Second generation flash drives have claimed to read at up to 30&nbsp;MB/s and write at about half that rate, which was about 20 times faster than the theoretical transfer rate achievable by the previous model, USB&nbsp;1.1, which is limited to 12&nbsp;Mbit/s (1.5&nbsp;MB/s) with accounted overhead.<ref>{{cite web|url=http://www.diffen.com/difference/USB_1.0_vs_USB_2.0|title=USB 1.0 vs. USB 2.0|publisher=Diffen|access-date=22 December 2014|archive-date=21 December 2014|archive-url=https://web.archive.org/web/20141221111405/http://www.diffen.com/difference/USB_1.0_vs_USB_2.0|url-status=live}}</ref> The effective transfer rate of a device is significantly affected by the data access pattern.<ref>{{cite web|url=https://www.usenix.org/legacy/event/usenix09/tech/full_papers/vandebogart/vandebogart_html/index.html|title=Reducing Seek Overhead with Application-Directed Prefetching|website=Usenix.org|publisher=Usenix|access-date=22 December 2014|archive-date=25 January 2022|archive-url=https://web.archive.org/web/20220125214635/https://www.usenix.org/legacy/event/usenix09/tech/full_papers/vandebogart/vandebogart_html/index.html|url-status=live}}</ref>

By 2002, USB flash drives had [[USB 2.0]] connectivity, which has 480&nbsp;[[megabit|Mbit]]/s as the transfer rate upper bound; after accounting for the protocol overhead {{citation needed span|date=June 2022|text=that translates to a 35&nbsp;[[Megabyte|MB]]/s effective throughput.|reason=Previously used source not only gives a different value (40&nbsp;MB/s), but is itself linking Wikipedia as its source.}} That same year, Intel sparked widespread use of second generation USB by including them within its laptops.<ref name=":2">{{Cite news|url=https://www.cnet.com/news/want-a-laptop-with-usb-3-0-the-few-the-proud/|title=Want a laptop with USB 3.0? The few, the proud|date=2010-09-19|work=CNET|access-date=2018-10-10|language=en|archive-date=2018-10-10|archive-url=https://web.archive.org/web/20181010174343/https://www.cnet.com/news/want-a-laptop-with-usb-3-0-the-few-the-proud/|url-status=live}}</ref>

By 2010, the maximum available storage capacity for the devices had reached upwards of 128&nbsp;GB.<ref name=":1">{{cite news|url=http://www.time.com/time/specials/packages/article/0,28804,2023689_2023703_2023613,00.html|archive-url=https://web.archive.org/web/20101028085259/http://www.time.com/time/specials/packages/article/0,28804,2023689_2023703_2023613,00.html|url-status=dead|archive-date=October 28, 2010|title=All-Time 100 Gadgets|date=2010-10-25|magazine=Time}}</ref> [[USB 3.0]] was slow to appear in laptops. Through 2010, the majority of laptop models still contained only USB 2.0.<ref name=":2" />

In January 2013, tech company Kingston, released a flash drive with 1&nbsp;TB of storage.<ref>{{Cite news|url=https://www.usatoday.com/story/technologylive/2013/01/09/kingston-terabyte-flash-drive-ces/1820159/|title=Kingston unveils 1 terabyte flash drive|work=USA Today|access-date=2018-10-10|language=en|archive-date=2018-10-10|archive-url=https://web.archive.org/web/20181010174422/https://www.usatoday.com/story/technologylive/2013/01/09/kingston-terabyte-flash-drive-ces/1820159/|url-status=live}}</ref> The first [[USB 3.1]] [[USB-C|type-C]] flash drives, with read/write speeds of around 530&nbsp;MB/s, were announced in March 2015.<ref>{{cite web|url=http://www.gizmofusion.com/2015/03/pk-the-worlds-first-usb-kit-with-3-1-technology/|title=PK: the World's First USB Kit with 3.1 technology|access-date=1 June 2016|archive-date=31 May 2016|archive-url=https://web.archive.org/web/20160531121125/http://www.gizmofusion.com/2015/03/pk-the-worlds-first-usb-kit-with-3-1-technology/|url-status=live}}</ref> By July 2016, flash drives with 8 to 256&nbsp;GB capacity were sold more frequently than those with capacities between 512&nbsp;GB and 1&nbsp;TB.<ref name="digitaltrends.com" /><ref name="techradar1" /> In 2017, Kingston Technology announced the release of a 2-TB flash drive.<ref>{{Cite news|url=https://money.cnn.com/2017/01/05/technology/kingston-technology-biggest-flash-drive-two-terabytes/index.html|title=The world's biggest flash drive can store more than 160 HD movies|last=Mullen|first=Jethro|work=CNNMoney|access-date=2018-10-10|archive-date=2018-10-10|archive-url=https://web.archive.org/web/20181010215055/https://money.cnn.com/2017/01/05/technology/kingston-technology-biggest-flash-drive-two-terabytes/index.html|url-status=live}}</ref> In 2018, SanDisk announced a 1&nbsp;TB USB-C flash drive, the smallest of its kind.<ref>{{Cite web|url=https://www.theverge.com/circuitbreaker/2018/1/9/16867044/sandisk-prototype-1tb-usb-c-flash-drive-worlds-smallest-ces-2018|title=SanDisk shows off the world's smallest 1TB USB-C flash drive at CES|website=TheVerge.com|date=9 January 2018|access-date=18 December 2019|archive-date=18 December 2019|archive-url=https://web.archive.org/web/20191218061916/https://www.theverge.com/circuitbreaker/2018/1/9/16867044/sandisk-prototype-1tb-usb-c-flash-drive-worlds-smallest-ces-2018|url-status=live}}</ref>

{| border="1" cellpadding="4" cellspacing="0" style="float:right; background:#f9f9f9; border:1px #aaa solid; border-collapse:collapse; margin-left:1em;"
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| style="background:#e7e7e7; text-align:center;" colspan="2"|
[[File:Usbkey internals.jpg|350px]]<br />'''Internals of a typical USB flash drive'''
|-
!1
|USB Standard-A, "male" plug
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!2
|USB mass storage controller device
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!3
|Test point
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!4
|[[Flash memory|Flash memory chip]]
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!5
|[[Crystal oscillator]]
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!6
|[[LED]] (Optional)
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!7
|[[Write protection|Write-protect]] switch (Optional)
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!8
|Space for second flash memory chip
|}

On a USB flash drive, one end of the device is fitted with a single [[USB plugs|Standard-A USB plug]]; some flash drives additionally offer a [[micro USB]] or USB-C plug, facilitating data transfers between different devices.<ref>{{cite web |last=Broida |first=Rick |url=http://reviews.cnet.com/8301-19736_7-57615094-251/pkparis-unveils-worlds-smallest-android-flash-drive/ |title=PKparis unveils world's smallest Android flash drive &#124; Android Atlas - CNET Reviews |publisher=Reviews.cnet.com |date=2013-12-10 |access-date=2014-02-19 |archive-date=2014-02-19 |archive-url=https://web.archive.org/web/20140219215734/http://reviews.cnet.com/8301-19736_7-57615094-251/pkparis-unveils-worlds-smallest-android-flash-drive/ |url-status=live }}</ref>