The USB Promoter Group has announced the upcoming release of the USB4 specification. The new standard is based on Intel’s Thunderbolt protocol and supports a range of features, including data transfer rates of up to 40 Gbps, display interfaces, and power delivery. The detailed USB4 specification will be published in the middle of 2019.

The USB4 specification will be based on the Thunderbolt protocol that Intel has contributed to the USB Promoter Group. The new interface will use USB Type-C connectors and will maintain backwards compatibility with USB 2.0, USB 3.2, and Thunderbolt 3 interfaces.  The maximum data transfer rate supported by the new USB4 interface is 40 Gbps over 40 Gbps-certified cables. Also, USB4 will support various display protocols, and power delivery.

The USB4 standard will be officially ratified in the middle of 2019. At present over 50 companies are actively participating in the final stages of development of the draft USB4 specification.


Based on what we know about the USB4 specification at this point, the new standard will use the Thunderbolt protocol, but it will not be exactly Thunderbolt 3 as its functionality will likely be different.

USB Specifications
  USB 1.0 USB 2.0 USB 3.2 Gen 1 USB 3.2
Gen 2
USB 3.2
Gen 2x2
Alternative Branding - High Speed Super
Bandwidth 12 Mbps 480 Mbps 5 Gbps 10 Gbps 20 Gbps 40 Gbps
Encoding 8b/10b 128b/132b
Introduction 1996 2001 2009
(USB 3.0)
(USB 3.1 Gen 2)
2017 2019

The contribution of the Thunderbolt 3 protocol to the USB Promoter Group essentially brings TB3 to mainstream PC platforms and enables various companies to integrate its support into their products. Meanwhile, Intel’s Ice Lake processors will be the first CPUs to support Thunderbolt 3 natively.

“Releasing the Thunderbolt protocol specification is a significant milestone for making today’s simplest and most versatile port available to everyone,” said Jason Ziller, General Manager, Client Connectivity Division at Intel. “By collaborating with the USB Promoter Group, we’re opening the doors for innovation across a wide range of devices and increasing compatibility to deliver better experiences to consumers.”

Related Reading

Sources: USB Promoter Group, Intel

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  • HStewart - Monday, March 4, 2019 - link

    If information is correct USB4 is TB3 - This is big win for both Thunderbolt 3 and customers - article sounds like it is TB3 with possibility USB 3.2 2x2 added on - but big question is why would any body make USB 3.2 2x2 devices with TB3 out there and fully supported in USB 4
  • jtd871 - Monday, March 4, 2019 - link

    Ya, sure sounds like Intel is wanting to muddy the waters and Osborne USB3.2 2x2.
  • HStewart - Monday, March 4, 2019 - link

    This is probably because Intel did announce they would open there specs for TB3 - which they could not until certain period of Apple exclusivity.
  • usama_ah - Monday, March 4, 2019 - link

    That blog link mentions that Intel PR affirmed TB was not exclusive to Apple, also it's from 2011 and about the first gen Thunderbolt product. And third parties have been making TB for years.

    As originally envisioned Apple came to Intel with the idea if a single versatile and high bandwidth port (Lightpeak) which eventually became Thunderbolt and Intel has been willing to license it from what I understand.

    The article your article links to has this sentence which is fun to read now that we're in a future if MacBook Airs and Pros with just USB-C TB3 ports:

    "Translation: Apple products in the near future could come equipped with only a Light Peak port (or ports) to handle your networking, display driving, and general connectivity."
  • HStewart - Tuesday, March 5, 2019 - link

    Apple had exclusive rights for first year of TB3.

    I find it also interesting that Apple has gone to USB-C and with TB3 open, Apple could use TB3 on iOS products - Also LightPeak is for TB3 which Intel created initially for Apple.
  • Rudde - Wednesday, March 6, 2019 - link

    "Why would any body make USB 3.2 2x2 devices with TB3 out there amd fully supported in USB 4"
    Because there are cpus/motherboards that only support the former. You don't want to make a usb flash drive that only 30% of your customerbase can use, do you?
  • ikjadoon - Thursday, March 7, 2019 - link

    It is a current ad. It literally writes USB4 in the ad.

    But, I see my error: that is not a "superset" / "subset" indication. It's just the design of the SmartArt they picked in PowerPoint...
  • tuxRoller - Tuesday, March 5, 2019 - link

    I would imagine it's a superset because of alt-mode.
  • skavi - Monday, March 4, 2019 - link

    is anyone aware of the difference between USB 4 and USB 3.2 + Thunderbolt 3?
  • HStewart - Monday, March 4, 2019 - link

    Big question if USB 3.2 2x2 device support on Thunderbolt 3? 20Gbs sure is.

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