It’s Official: USB4 Incorporates Thunderbolt 3

Posted on September 3, 2019 by Paul Thurrott in Hardware, Mobile, Windows 10 with 51 Comments

The USB Implementers Forum (USB-IF) today published the official USB4 specification, which is based on Thunderbolt 3.

“The USB4 specification is a major update to deliver the next-generation USB architecture that complements and builds upon the existing USB 3.2 and USB 2.0 architectures,” the organization announced. “The USB4 architecture is based on the Thunderbolt protocol specification recently contributed by Intel Corporation to the USB Promoter Group. It doubles the maximum aggregate bandwidth of USB and enables multiple simultaneous data and display protocols.”

To be clear, this is a good thing: Thunderbolt 3 functionality has been available via USB-C for several years now, but adoption has been spotty, with some PC makers mixing and matching between traditional USB-C ports and more powerful USB-C/Thunderbolt 3 ports. (Only one PC maker, Microsoft, has completely ignored Thunderbolt 3 for some reason.)

So what USB4 will provide is what we see today via USB-C/Thunderbolt 3 ports, a single, reversible connector that can deliver power, display, storage, and peripheral connectivity at speeds of up to 40 Gbps. It will be backward compatible with USB 2.0, USB 3.2, and Thunderbolt 3, too.

You can expect new PCs based on USB4 to begin appearing in the market as soon as early 2020. With the obvious exception of Microsoft, of course.

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Comments (51)

51 responses to “It’s Official: USB4 Incorporates Thunderbolt 3”

  1. JoePaulson

    No excuses now Microsoft! I hope my next laptop can be a surface laptop with USB 4.

  2. sentinel6671

    Good news.

    I won't be buying a new computer until I see this in the wild. I just hope that it actually helps with the clusterf**k position that the world is in now, with all the disparate plugs.

  3. brettscoast

    Excellent news hopefully once implemented takes us away from all the USB3 naming silliness

  4. bluesman57

    It will be called "Thunder Speed USB Ultra Turbo 7.2"

  5. mrdrwest

    USB4 is what Microsoft was waiting for.

  6. puggsly

    So will this port have a USB symbol or a Thunderbolt symbol? This is already confusing for most consumers and if it uses a USB logo how will w know if it us USB c 3.2 or USB c 4.0 with thunderbolt support?

  7. MikeGalos

    Any statement on whether there will be only ONE compatible version of USB 4 with USB Type C connector unlike the visually identical but massively incompatible hundreds of possible options for USB 3.x with USB Type C connector products?

    Will there be a unique new connector or at least some visual differentiation so people will have even the slightest clue whether their device or computer or cable will work before buying it and testing it?

  8. wright_is

    I expect to see a lot of devices offering 1 or 2 USB 4 ports and the rest offering USB 3 / USB-C.

    The problem with Thunderbolt is that it requires PCI lanes to be dedicated to the port and there are only a limited number of lanes available.

    Otherwise, great news.

  9. siv

    It would be nice if they could get us all onto a USB C style sockets and quietly lose all the other previous formats and also fix the issue where certain badly made cables can nix your PC!

  10. RonV42

    The confusion will always be there with Thunderbolt 3 being the real source. I have 4 lanes of PCI express exposed though USB-C / Thunderbolt and each USB-C socket has two lanes each. Every manufacturer has different implementations. Now how is a consumer supposed to understand this?

  11. glenn8878

    USB 4/C is not yet mainstream. Still using USB 2/A. Waiting for manufacturers to at least stop selling USB A phone chargers and external hard drives at minimum.

  12. huddie

    So the question that we're bound to get is "What's the difference between USB4 and Thunderbolt 3 ?" It seems that, unlike Thunderbolt 3, USB4 is backwards compatible with USB 3.2 Gen 2x2, so should provide up to 20Gbps on devices that support it. Heavens above the naming of this stuff is messed up.

  13. Scsekaran

    Still a lot of confusion. And it is a mess. I do not think USB4 is going to provide any more clarity. Thanks Intel for hijacking USB-C port for Thunderbolt and creating this mess.

    Is it compatible with AMD chipset / motherboards?

    There is nothing 'Universal' about USB 3 or USB4 anymore

  14. edward23144

    I am not against technology moving forward but I am not a fan of things like my 2017 Macbook Pro that only has USB-C ports when the world is barely even using that technology. If the Surface devices do finally support USB-C/Thunderbolt, lets hope they still include a USB-A port because buying lots of dongles.

  15. ReformedCtrlZ

    Unless MSFT has been waiting for USB4 knowing this would happen to make things an easier transition? Just a guess, but if everyone will be revolving around this standard that solves the issues of confusion and reliability of experience the team had brought up before about this issue.

  16. jaredthegeek

    This is great news. I have a computer with one USB C with TB and the others do not. Its idiotic at best.

    • wright_is

      In reply to jaredthegeek:

      Only partly. The processor and chipset only has a limited number of PCI lanes available, if every USB port had TB3 as well, there wouldn't be any left for things like memory, storage, GPU etc.

      • jimchamplin

        In reply to wright_is:

        And therefore we have the problem created by the artificial need to have a single connection.

        Its shitty UI for a single plug to be different things. Oh you can charge and use USB here, but that identical one over there can do it all. But don’t use this wire on that port.

        The USB folks, and I’m sure member company Apple was a main proponent, decided we need a THIN connection because reasons.

        The truth is that if a port offers different functionality it should be physically different to avoid user error.

        None of the technical reasons matter. Only the boneheaded design requirement of a single connection.

  17. jimchamplin

    So now PC makers can put a single USB 4 port and three USB 3.2 ports on a machine. And one of those 3.2 ports has TB3.

    They still can and will make a mockery of the whole thing.

  18. ianw789

    So with all this enthusiasm for Thunderbolt, have the DMA related security issues published earlier this year ("Thunderclap") been resolved, or just deemed too obscure to worry about?

    • rosyna

      In reply to ianw789:

      These aren’t new issues (they’re from 2016) and they’re addressed by using IOMMU and other virtualization techniques since macOS 10.12.4, Windows 10 1803, and Linux 5.0. For the latter, you may have to manually enable IOMMU protections in BIOS.

      • ianw789

        In reply to rosyna:

        As I read it, the vulnerabilities in the Feb 2019 paper ("Thunderclap: ExploringVulnerabilities in Operating System IOMMUProtection via DMA from Untrustworthy Peripherals") were specifically in IOMMU.

      • sandy

        In reply to rosyna:

        Microsoft have added protection in recent versions of Windows 10 Enterprise edition, but appallingly this protection is not available in Windows 10 Pro (like BitLocker is missing from Home edition).

        Not only do Microsoft need to have USB4 in their PCs, they must make these TB3/USB4 DMA protections available in all editions of Windows 10, and now (such as in Windows 19H2).

    • abillimore

      In reply to ianw789:

      As far as I understand these issues can only be mitigated (due to the nature of the access level required for performance reasons for one reason). Physical access is always going to be a problem for your security.

    • wright_is

      In reply to ianw789:

      You can't get around them without disabling DMA and this making Thunderbolt useless, at best you can mitigate the problem in software. Firewire had exactly the same fault for exactly the same reason, the TB team didn't take that into account when they released it.

      Then there is also the fact that it requires dedicated PCI lanes for each port and the processor and chipset only has a limited number of lanes available, which have to be shared with memory, storage, video and various other I/O tasks.

  19. dontbeevil

    "You can expect new PCs based on USB4 to begin appearing in the market as soon as early 2020. With the obvious exception of Microsoft, of course"

    Any proof?

    • karlinhigh

      In reply to dontbeevil:

      How is it that you respond to every single instance of "copycat" new products, but have not picked up on Paul's pet peeve with the Microsoft Surface product line? Proprietary charge connectors and lack of USB-C.

      In your defense, it looks like most articles on this topic were under Premium.

      • dontbeevil

        In reply to karlinhigh:

        I don't care about "copycat" products, I care about different treatment when it's up to apple or someone else on this website

        • curtisspendlove

          In reply to dontbeevil:

          I care about different treatment when it's up to apple or someone else on this website

          Seriously? Paul calls out Apple more than anyone else (other than Microsoft, maybe) on this site. And in this case he's 100% right.

          Apple went to USB-C / Thunderbolt too soon.

          Microsoft is coming in way too late.

          But the market still hasn't flooded with USB-C stuff, as I think Apple expected.

          Hopefully v4 can solve the ambiguity that has made a lot of people apprehensive to switch over. Also, more phones are switching over, so that will help drive marketshare as well. (And lots of new laptops coming for the holiday season.)

          • dontbeevil

            In reply to curtisspendlove:

            "Gmail No Longer Gives You an Excuse to Send Emails With Spelling and Grammar Mistakes"

            For some reasons they forgot to say that already provide the same feature for ages, but when it comes to MS, they really pay attention to put the emphasis on copy

            "Microsoft Copied the iPhone’s Animoji and Made It More Accessible"

            Oh they forgot to write copy also when it comes to

            "In-Display Fingerprint Scanners Will Make a Debut on the iPhone in 2021"


            "Apple Introduces New Migration Feature for iPhones"


            "Apple Testing Face ID and Touch ID Sign-In for"


            "Google Services Going Passwordless on Android"

            But suddenly they remembered again that apple has something similar to point out here:

            "Xiaomi, Oppo, and Vivo Announce New AirDrop-inspired File Transfer feature"

            (and of course there was nothing similar before airdrop…ehm bluetooth/nfc file transfer)

            And they forgot to mention products with similar features again

            "Apple Watch Reportedly Getting Built-In Sleep Tracking"

            "Apple’s Tag Device for Tracking Personal Items Detailed in New Leak"

  20. Stooks

    I own two laptops with USB-C thunderbolt ports since 2017 and I have yet to use a native USB-C device.

    I would wager that 98+% of the USB devices in the world use a USB-A connector and can't take advantage of anything over USB 3.0 (480 megabits) speed.

    I am not against technology moving forward but I am not a fan of things like my 2017 Macbook Pro that only has USB-C ports when the world is barely even using that technology. If the Surface devices do finally support USB-C/Thunderbolt, lets hope they still include a USB-A port because buying lots of

  21. jasonoki

    I still don't know how to the difference between the other USB c standards