The USB Promoter Group is hard at work developing the USB4 specification. We met with them at Computex this year, and the good news is that the spec is in its 0.96 version and things are proceeding quickly. The group believes that retail products featuring USB4 will be available by the end of 2020.

Update 16/6: The current USB4 spec is at 0.96.

Being based on Thunderbolt 3 technology and offering up to 40 Gbps bandwidth, USB4 promises to be more than that. In fact, so much more that the USB Promoter Group is considering a new logotype and branding scheme. The current one is already complex enough, so expect some kind of simplification on that front. Meanwhile, USB4 will be backwards compatible with existing USB Type-C devices.

When it comes to availability, USB-IF seems to be optimistic that the specification will be finalized this Summer and actual USB4-supporting devices will be available by the end of 2020. Since Intel knows how to build Thunderbolt 3 controllers, it will certainly use its expertise developing USB4 controllers eventually.

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  • DanNeely - Wednesday, June 12, 2019 - link

    " USB4 promises to be more than that. In fact, so much more that the USB Promoter Group is considering a new logotype and branding scheme. The current one is already complex enough, so expect some kind of simplification on that front. "

    Actually what I'm expecting is more like: USB4 gen4 4x4 40gbps Ludicrous Speed OMGWTFLOLBBQ
  • repoman27 - Wednesday, June 12, 2019 - link

    I dunno, Apple was pretty involved for a while there over at the USB-IF, so maybe we'll get something like "Microburst" for the trademark, along with an understated yet evocative logo (and no obvious connection to the technologies which preceded it).
  • Herbertificus - Sunday, June 30, 2019 - link

    "USB4 gen4 4x4 40gbps Ludicrous Speed OMGWTFLOLBBQ"

    LOL !

    Don't give 'em any ideas.
  • KimGitz - Wednesday, June 12, 2019 - link

    With Intel contributing to the USB4 standard they already have a significant advantage because nobody understands TB3 better than them and USB4 is based on Thunderbolt 3. If you look at the slides for Ice Lake, Thunderbolt 3 is integrated to the CPU but two things stood out for me:
    1. On the CPU block it is referenced as USB-C and Thunderbolt 3 interchangeably.
    2. On another slide the protocol between two Thunderbolt 3 controllers is referenced as 40G USB4 Tx and 40G USB4 Rx.
    Since the specification is already at 0.7 and the full spec is expected to be ratified soon, there is not much going to change.
    Intel is supposed to release Ice Lake-SP next year alongside support for PCIe 4.0, having Thunderbolt integrated in the CPU will mean that a lot of the issues we have with an external controller and PCIe 4.0 can be resolved right on the CPU where Thunderbolt and PCIe is concerned. You can’t get any closer than on die design.
    Ice Lake is therefore USB4 ready with support of up to 4 USB-C ports on laptops, 2 on each side.
    I was glad to see ASRock come out with Motherboards that support TB3 for Ryzen 3000 CPUs. I think it will be a matter of a software patch to get TB3 to support USB4 even on AMD systems.
  • repoman27 - Wednesday, June 12, 2019 - link

    Ice Lake-SP, being targeted at servers, probably won't include Thunderbolt at all. Tiger Lake U and Y, which are due as early as Q2 2020, hopefully will have PCIe 4.0 and will also probably be the first official USB4 products.

    The slides that you referred to (which I believe are these ones here: ) indicate that Icelake U will have the equivalent of a PCIe 3.0 x4 link on the back end for each Thunderbolt port, in other words double the width of the interface on discrete controllers. But until such time as Intel releases a client platform with PCIe 4.0, we probably shouldn't expect to see any matching discrete controllers with PCIe 4.0 for Thunderbolt devices

    Also notable is that Icelake supports DisplayPort 1.4 HBR3 with DSC 1.1, so I imagine we might see some new Ridge out later this year, unless Titan Ridge is already DSC 1.1 capable.
  • KimGitz - Wednesday, June 12, 2019 - link

    Intel wants Thunderbolt to dominate USB, there are a number of advantages Thunderbolt has over USB that benefit workstations. Intel favours Thunderbolt over any I/O even on workstations. The adoption of Thunderbolt in server Motherboards is slow but it is happening. Supermicro announced support for Thunderbolt on their workstation servers awhile back and should be working on Thunderbolt 3 certification. Obviously Apple has their new workstation, Mac Pro with upto 12 TB3 ports.
  • KimGitz - Wednesday, June 12, 2019 - link

    Titan Ridge replaced Alpine Ridge mainly because of DisplayPort 1.4 support. HBR3 was introduced with DisplayPort 1.3. DisplayPort 1.4 adds support for Display Stream Compression 1.2 (DSC) which Titan Ridge supports.
  • repoman27 - Wednesday, June 12, 2019 - link

    Icelake-SP lacks an integrated GPU, and therefore it will not have Thunderbolt on die. Workstations will have to get by with discrete Thunderbolt controllers for a while yet.

    DSC support is an entirely optional feature of the DP 1.4 spec. NVIDIA Turing, AMD Navi, and Intel Gen11 GPUs are the first to support DSC despite several previous architectures being certified DisplayPort 1.4 compliant. Not to mention things like Icelake having DP 1.4 outputs but only DSC 1.1 capability. There is no indication one way or the other regarding Titan Ridge's ability to transport streams using DSC.
  • KimGitz - Friday, June 14, 2019 - link

    An integrated Thunderbolt controller from the CPU will use DisplayPort lanes from a Discrete GPU. Typically there would be a Display Input. Thunderbolt controllers are not graphics processors they can support standards long before they are available on graphics processors. The Titan Ridge supported DisplayPort 1.4 while Intel iGPUs only supported DisplayPort 1.2, 1.3. The first DisplayPort 1.4 support is expected with Gen 11 of iGPUs from Intel. The Titan Ridge was announced in January 2018 while the DisplayPort 1.4 and DSC 1.2 spec was announced almost 2 years earlier in March 2016. By January 2017 VESA had already started a program to fast track certification for DisplayPort 1.4 Alt Mode on USB-C. DisplayPort 1.4 support was the main feature for Titan Ridge.
  • repoman27 - Friday, June 14, 2019 - link

    Engineering samples of Ice Lake-SP already exist, and not one source that I'm aware of has said anything about Thunderbolt. Besides, there's no point in integrating a feature if you can only integrate 50% of the back end. And there is no way Intel would waste the die space and reduce yields of the LCC / HCC / XCC dies.

    Titan Ridge was developed for release alongside Intel Gen10 Graphics, which included support for DP 1.4. Cannon Lake technically "shipped for revenue" before Titan Ridge, but it also never shipped with an enabled GPU. By far the largest customer for Thunderbolt is Apple, and if they wanted Titan Ridge, Intel was going to sell them Titan Ridge, despite the fact that it would give competing GPUs an advantage. Historically, they were content to allow Thunderbolt to hobble the display output capabilities of discrete GPUs in order to level the playing field with their own offerings. But in reality, the groups that deal with display controller and transport IP at Intel probably work together or at least not in total isolation, so that the source and sink implementations work together as well as possible.

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