from Hacker News

USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

by BogdanPetre on 3/4/19, 8:09 PM with 271 comments

  • by WhitneyLand on 3/4/19, 9:53 PM

    What's optional?

    That's the most important thing to know is what's optional in the spec.

    That could make it great or a major pain. I'm referring to how many features the specification defines as "optional" for manufactures and that the USB organization requires for logos.

    This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even more permutations and sub-features. Oh, you wanted charging and found one that has it? Know how much power it enough or overkill? It could provide 15 watts, 100 watt, etc. Think you'll just google the specs page? Sure, they never miss providing any of these details or make any mistakes.

    Whether USB4 means one thing with nothing optional (or at least a very small number of combinations), will probably determine how much you like it or get annoyed by it.

    HP even made it worse with a laptop USB-C port that could technically be used for certain docking functionality but tried to fud-deny allowing it for marketing reasons.

  • by sp332 on 3/4/19, 8:21 PM

    Ars Technica just wrote an article about the confusing names of USB versions https://arstechnica.com/gadgets/2019/02/usb-3-2-is-going-to-... and now they have another one about this name. https://arstechnica.com/gadgets/2019/03/thunderbolt-3-become...

  • by davnicwil on 3/4/19, 8:32 PM

    As someone who knows next to nothing about how USB actually works and just uses it, what goes into making each USB generation faster?

    At the physical layer, is it the materials in the cables are getting better? Or new ways of using the same materials?

    At the protocol layer, is it newly developed computer science theory being applied or is it just old fashioned pragmatic engineering iteration, looking at usage and making the existing protocols more efficient with tricks and shortcuts etc?

  • by gumby on 3/4/19, 9:03 PM

    > ... it will not be exactly Thunderbolt 3 as its functionality will likely be different.

    I don't understand how this isn't simply ratifying/renaming current TB3-on-Type-C-connectors and this cryptic sentence in the page doesn't help. Anybody know?

    This isn't to say that such a renaming might not be a good idea! But it would be nice to know if my current Type C ports with TB and DB support were in fact already "USB 4.0."

    Also: speaking of nomenclature: notice that according to the press kit slide show, USB 3.1 Gen 2, USB 3.2 Gen 2x2, and USB4 all have the same "Alternative Branding": "Super Speed+". Madness!

  • by penagwin on 3/4/19, 8:36 PM

    Here's an idea, let's make different connector shapes depending on the cable/connector's capabilities, lets do one for connectors that support display, one for power, one for thunderbolt, that way they're easy for the average consumer to identify!

    Oh wait that's the issue USB was supposed to solve in the first place....

  • by matthewmacleod on 3/4/19, 9:22 PM

    So… maybe I'm missing the details, but is this just basically rebranding TB3 as USB4? That would make a lot of sense, if so.

    Edit: Ah, I missed "it will not be exactly Thunderbolt 3 as its functionality will likely be different". That's a clear as mud, then.

  • by bits on 3/5/19, 12:54 AM

    Whoa. Does the addition of Thunderbolt imply that all USB4 host systems are exposed to DMA attacks[0]?

    Doesn't this open up every USB system (all systems?) to arbitrary, uncontrolled memory access including silently flashing new firmware/microcode to system components?

    0: https://en.wikipedia.org/wiki/DMA_attack

  • by chkaloon on 3/4/19, 8:27 PM

    Not USB 3.2 Gen 2x2x2?? Come on, consistency people!

  • by zapzupnz on 3/5/19, 12:03 AM

    USB 4? You sure they don't mean USB 3.4 Revision 4 UltraSpeed HyperBus XP for Workgroups 3.11 Xtreme Edition?

  • by cm2187 on 3/4/19, 9:24 PM

    I'd be curious about 40Gbps for what cable length. TB3 is great, you can in theory dock a laptop with a single cable that will do charging, 10gbe, USB hub, etc, but with a max 50cm cable, which makes it quite "un-lappable". I'd love to do the same with a 2m cable.

  • by gigatexal on 3/4/19, 8:45 PM

    Royalty free is the huge boon here.

  • by artiscode on 3/4/19, 9:02 PM

    Honestly, I'm waiting for old USB(USB A, USB B) to be deprecated and USB C become the new universal USB. As in ATM machine, you get the drill. Current USB cable situation is a mess - my phone is USB C, but it came with a USB A to USB C cable. Good thing I can connect it to my 2017 MacbookPro using it's original USB C charging cable! However then I can't charge. Sometimes I use a USB C to female USB A dongle to use my phone's USB A male to USB C. And the whole thing has become expensive, good USB C cables seem to be made out of gold. Life would become so much easier if everything was USB C to USB C

  • by MichailP on 3/4/19, 8:36 PM

    Does this also mean that soon every computer will be making noise/radiating waves around 40GHz? Can someone with more depth in this area shine some light on this?

  • by koala_man on 3/4/19, 8:48 PM

    tl;dr: Intel made Thunderbolt 3 royalty free in 2018, so now it's essentially being adopted as USB4.

    I had to look up what the point of 40Gbps was, and the industry evangelization site https://thunderbolttechnology.net/ explains that it will allow driving one 5k display or two 4k displays, which is not possible with the 20Gbps offered by USB 3.2 or Thunderbolt 2.

    This also helps external GPUs, where TB2/USB3.2 is the equivalent of 2.5 PCI-e 3.0 lanes, while TB3/USB3 is 5.

    With that, it seems the goal is to be a viable alternative to PCI-e and HDMI, rather than just improve on today's USB3 speeds for existing device classes.

  • by walterbell on 3/4/19, 8:19 PM

    Will it be possible to connect a Thunderbolt 3 Macbook or Intel Ice Lake PC via USB-C cable to a USB 4.0 device and obtain 40Gbps throughput?

  • by alacombe on 3/4/19, 8:54 PM

    This is a poisoned gift, there was a twitter conversation posted a couple weeks ago about the cluterf*ck that thunderbolt is... quite a scary read :-/

    https://twitter.com/whitequark/status/1097777102563074048

  • by aboutruby on 3/4/19, 10:46 PM

  • by modeless on 3/4/19, 9:14 PM

    Is it an unpopular opinion that USB is already fast enough and has enough features and USB implementers should instead work on cost reduction and compatibility so that we can all move away from USB 2 and pre-type-C connectors?

  • by Budabellly on 3/4/19, 10:12 PM

    This is quite meaningful for external graphics solutions, PCI peripheral devices, and other modular pc components.

  • by nintendo1889 on 3/4/19, 8:51 PM

    I am starting to see computers with USB C on the host side. The future of one single connector to rule them all will be here soon. Wait a minute, we already had that, it was usb 2.0?!?!

  • by goalieca on 3/4/19, 8:30 PM

    I’d love to ditch HDMI (even on my television!)

  • by snazzycalynx on 3/5/19, 7:45 AM

    "The detailed USB4 specification will be published in the middle of 2019 and half-assed, cheap hardware that only implements a subset of the total features list in order to cut corners on cost but still use the new name should appear in 2030 behind flimsy out-of-spec connectors and loose, easily damaged cables."

    I had to add a few things to manage expectations and more accurately reflect reality, but I think we've got it now.

  • by Halluxfboy009 on 3/5/19, 10:11 AM

    Can it make DP1.4 and HDMI 2.1 obsolete?