Editing USB (section)

=== Thunderbolt ===
{{Main|Thunderbolt (interface)}}
Thunderbolt combines [[PCI Express]] and [[DisplayPort]] into a new serial data interface. Original Thunderbolt implementations have two channels, each with a transfer speed of 10&nbsp;Gbit/s, resulting in an aggregate unidirectional bandwidth of 20&nbsp;Gbit/s.<ref>{{cite web |url=https://thunderbolttechnology.net/tech/how-it-works |title=How Thunderbolt Technology Works: Thunderbolt Technology Community |website=ThunderboltTechnology.net |access-date=22 January 2014 |url-status=live |archive-url=https://web.archive.org/web/20140210063142/https://thunderbolttechnology.net/tech/how-it-works |archive-date=10 February 2014 }}</ref>

[[Thunderbolt 2]] uses link aggregation to combine the two 10&nbsp;Gbit/s channels into one bidirectional 20&nbsp;Gbit/s channel.<ref>{{cite web |title=What you need to know about Thunderbolt 2 |url=https://www.macworld.com/article/222636/what-you-need-to-know-about-thunderbolt-2.html#:~:text=What%20is%20Thunderbolt%202%3F,20%20Gbps%20bi%2Ddirectional%20channel. |first=Jim |last=Galbraith |date=2 January 2014 |access-date=18 June 2021 |website=Macworld |publisher=IDG Communications, Inc. |archive-date=24 June 2021 |archive-url=https://web.archive.org/web/20210624202741/https://www.macworld.com/article/222636/what-you-need-to-know-about-thunderbolt-2.html#:~:text=What%20is%20Thunderbolt%202%3F,20%20Gbps%20bi%2Ddirectional%20channel. |url-status=live }}</ref>

[[Thunderbolt 3]] and [[Thunderbolt 4]] use [[USB-C]].<ref>{{cite web|url=https://www.cnet.com/news/thunderbolt-3-and-usb-type-c-join-forces-for-one-port-to-rule-them-all/|title=One port to rule them all: Thunderbolt&nbsp;3 and USB Type-C join forces|archive-url=https://web.archive.org/web/20150602195337/http://www.cnet.com/news/thunderbolt-3-and-usb-type-c-join-forces-for-one-port-to-rule-them-all/|archive-date=2 June 2015|url-status=live|access-date=2 June 2015}}</ref><ref>{{cite web |url=https://www.engadget.com/2015/06/02/thunderbolt-3-usb-c/ |title=Thunderbolt&nbsp;3 is twice as fast and uses reversible USB-C |date=2 June 2015 |access-date=2 June 2015 |url-status=live |archive-url=https://web.archive.org/web/20150603000428/http://www.engadget.com/2015/06/02/thunderbolt-3-usb-c/ |archive-date=3 June 2015  }}</ref><ref>{{cite web |url=https://arstechnica.com/gadgets/2015/06/thunderbolt-3-embraces-usb-type-c-connector-doubles-bandwidth-to-40gbps/ |title=Thunderbolt&nbsp;3 embraces USB Type-C connector, doubles bandwidth to 40&nbsp;Gbps |author=Sebastian Anthony |date=2 June 2015|website=Ars Technica |access-date=2 June 2015 |url-status=live |archive-url=https://web.archive.org/web/20150609183247/https://arstechnica.com/gadgets/2015/06/thunderbolt-3-embraces-usb-type-c-connector-doubles-bandwidth-to-40gbps/ |archive-date=9 June 2015  }}</ref> Thunderbolt&nbsp;3 has two physical 20&nbsp;Gbit/s bi-directional channels, aggregated to appear as a single logical 40&nbsp;Gbit/s bi-directional channel. Thunderbolt 3 controllers can incorporate a USB&nbsp;3.1 Gen&nbsp;2 controller to provide compatibility with USB devices. They are also capable of providing DisplayPort Alternate Mode as well as DisplayPort over USB4 Fabric, making the function of a Thunderbolt&nbsp;3 port a superset of that of a USB&nbsp;3.1 Gen&nbsp;2 port.

DisplayPort Alternate Mode 2.0: USB4 (requiring USB-C) requires that hubs support DisplayPort 2.0 over a USB-C Alternate Mode. DisplayPort 2.0 can support 8K resolution at 60&nbsp;Hz with HDR10 color.<ref name="displayport">{{cite web |title=New DisplayPort spec enables 16K video over USB-C |url=https://www.theverge.com/2020/4/30/21242445/vesa-displayport-alt-mode-2-0-usb-4-4k-144hz-hdr-8k-16k-displays |first=Jon |last=Porter |date=30 April 2020 |access-date=18 June 2021 |website=The Verge |publisher=Vox Media, LLC |archive-date=15 April 2021 |archive-url=https://web.archive.org/web/20210415051447/https://www.theverge.com/2020/4/30/21242445/vesa-displayport-alt-mode-2-0-usb-4-4k-144hz-hdr-8k-16k-displays |url-status=live }}</ref> DisplayPort 2.0 can use up to 80&nbsp;Gbit/s, which is double the amount available to USB data, because it sends all the data in one direction (to the monitor) and can thus use all eight data wires at once.<ref name="displayport"/>

After the specification was made royalty-free and custodianship of the Thunderbolt protocol was transferred from Intel to the USB Implementers Forum, Thunderbolt 3 has been effectively implemented in the USB4 specification – with compatibility with Thunderbolt 3 optional but encouraged for USB4 products.<ref>{{cite web|title=USB4 Thunderbolt3 Compatibility Requirements Specification|url=https://www.usb.org/sites/default/files/USB4%E2%84%A2%20Thunderbolt3%E2%84%A2%20Compatibility%20Requirements%20Specification%20Rev%201.0%20-%2020210129_0.pdf|date=January 2021|access-date=1 January 2021|website=USB|publisher= USB Implementers Forum |archive-date=19 October 2021|archive-url=https://web.archive.org/web/20211019074211/https://usb.org/sites/default/files/USB4%E2%84%A2%20Thunderbolt3%E2%84%A2%20Compatibility%20Requirements%20Specification%20Rev%201.0%20-%2020210129_0.pdf|url-status=live}}</ref>