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How Many Kinds of USB-C To USB-C Cables Are There? (kernel.org) 116

From a blog post: Classic USB from the 1.1, 2.0, to 3.0 generations using USB-A and USB-B connectors have a really nice property in that cables were directional and plugs and receptacles were physically distinct to specify a different capability. A USB 3.0 capable USB-B plug was physically larger than a 2.0 plug and would not fit into a USB 2.0-only receptacle. For the end user, this meant that as long as they have a cable that would physically connect to both the host and the device, the system would function properly, as there is only ever one kind of cable that goes from one A plug to a particular flavor of B plug. Does the same hold for USB-C? Sadly, the answer is no. Cables with a USB-C plug on both ends (C-to-C), hitherto referred to as "USB-C cables", come in several varieties. Here they are, current as of the USB Type-C Specification 1.4 on June 2019:
USB 2.0 rated at 3A,
USB 2.0 rated at 5A,
USB 3.2 Gen 1 (5gbps) rated at 3A,
USB 3.2 Gen 1 (5gbps) rated at 5A,
USB 3.2 Gen 2 (10gbps) rated at 3A,
and USB 3.2 Gen 2 (10gpbs) rated at 5A.

We have a matrix of 2 x 3, with 2 current rating levels (3A max current, or 5A max current), and 3 data speeds (480mbps, 5gbps, 10gpbs). Adding a bit more detail, cables 3-6, in fact, have 10 more wires that connect end-to-end compared to the USB 2.0 ones in order to handle SuperSpeed data rates. Cables 3-6 are called "Full-Featured Type-C Cables" in the spec, and the extra wires are actually required for more than just faster data speeds. "Full-Featured Type-C Cables" are required for the most common USB-C Alternate Mode used on PCs and many phones today, VESA DisplayPort Alternate Mode. VESA DP Alt mode requires most of the 10 extra wires present in a Full-Featured USB-C cable.

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How Many Kinds of USB-C To USB-C Cables Are There?

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  • Two (Score:5, Funny)

    by mschaffer ( 97223 ) on Wednesday July 17, 2019 @02:55PM (#58941036)

    There are two kinds: The one that works and the other one.

    • You got that wrong...There are more kinds in the "other one" type.

      This kind has one common theme: China.

      In this category, there are as many as the prospective buyers/importers in the west, care to specify.

      Those Chinese!!!

    • There are two kinds: The one that works and the other one.

      You mean, "The one that works and the one I have in my hand."

      I bought some USB-C cables after finding out that the cable that came with my laptop for charging was the USB 2.0 rated at 5A type. I wanted a USB-C cable of the USB 3.2 type, at any current rating, to connect two devices together. After I got it in the mail I realized I had one made for 5 Gbps rather than the 10 Gbps I thought I had ordered.

      Oh, well, such is life. As much of a headache USB-C might be it's still far better than most standards f

      • Is anyone else reminded by this USB cable crapfest of the codebook scene from "A Day at the Races"? Oh, you want that? You'll need to buy this extra thing. What, a blue one? Well then you need this. Oh, you want to plug it in as well? Then you'll need this other one.
    • You mean like to 10 kinds of people who either understand binary or don't?
  • by Anonymous Coward

    Duh.

  • by itsme1234 ( 199680 ) on Wednesday July 17, 2019 @03:01PM (#58941072)

    There are devices that can both be powered and provide power over USB-C. What happens when you connect two together (and very often yes, it does make sense to, like powerbanks and laptops, yes there are power banks that can easily power many if not all USB-C laptops, I've seen up to 20V&4.5A)? Sometimes you want to charge the powebank from the laptop, sometimes to power the laptop from the powerbank. But I have yet to see any way to control the direction, either in the powerbank, laptop's OS or BIOS.

    • There are devices that can both be powered and provide power over USB-C. What happens when you connect two together?

      They auto-negotiate and do what you expect. My laptop uses USB-C both for charging and for providing power to peripherals. I just plug in the cable and it works.

      I suppose there are some weird corner cases, such as charging a battery pack from a laptop, that don't work, but I have never needed to do that, and I doubt if most other normal people do either.

      • Powerbank and laptop is corner case?
        What about USB-C hubs and laptop (there are some that do exactly the same, can power the laptop and be powered by it)?

        • An auto negotiation that has a very clear and easy definition: Is the hub currently plugged into an external supply or not. That isn't an ambiguous case. You can't power a laptop through a magic USB hub and it doesn't make sense to power a hub that is already plugged in.

          The *only* cases I've heard were a problem where people have plugged laptops into powerpacks. Every other use case has a very defined charging direction. And that's only for the stupid power packs that don't define it (all the ones in our ho

        • Powerbank and laptop is corner case?

          Using a battery-pack to power a laptop is normal use, and works fine.

          Using a laptop to charge a battery-pack is definitely a corner case. I have a hard time imagining a scenario where that would make sense if both are charged with USB-C.

          But, since current PowerBanks have separate USB ports for "in" and "out", you should be able to use it in either direction.

          What about USB-C hubs and laptop (there are some that do exactly the same, can power the laptop and be powered by it)?

          That works fine. If the hub is unpowered, the laptop provides power. If the hub is powered externally, it will charge the laptop. All of this works

          • Using a laptop to charge a battery-pack is definitely a corner case. I have a hard time imagining a scenario where that would make sense if both are charged with USB-C.

            I really don't understand why people think it's a corner case to charge a power bank from the laptop as long as THERE ARE POWER BANKS MARKETED FOR LAPTOPS. Sure, they will charge the laptop and at some point YOU WANT TO CHARGE THE POWER BANK AS WELL (yes, in this house we obey the laws of thermodynamics). And sure, you might not want to carr

            • >What is the protocol used for negotiating?

              The USB PD protocol.

              There will always be a combination where it's not clear whether a battery is to be a source or a sink. But it's hardly common and the default for power to go from a wall socket to everything is sound for all use cases I can think of.

          • You can imagine the discussions in the USB PD group when they were working through all the combinations of power flow between sources, sinks, source/sinks, hubs, powered hubs, battery storage hubs and so on.

            Fun times.

            • Yea, I can imagine but I think in reality they went to quote Duke Nukem (sic) "Let God sort 'em out!". Or left it to the manufacturers. For now what I knew and what I learned from yesterday is that Android phones have some control over the direction (at least of the "data" host or not - but that seems to control the power too), there's some Ravpower (I think it was quoted earlier) powerbank that can be controlled from its button and for the new ipads pro it's literally random (documented, just plug again if

      • They auto-negotiate and do what you expect.

        I guess with a power back that might mean charging my laptop.

        But I also think in some cases I might well want to charge the portable charger from the laptop, so I could top it off and have more power wandering around. That could also be expect, or hope for, depending on my plans.

        An interesting case to consider is how Apple handles this choice. For at least one pairing, a USB-C iPad Pro connected to another USB-C iPad Pro, it will randomly decide (or maybe based on

        • But I also think in some cases I might well want to charge the portable charger from the laptop

          I just went to Amazon and looked at the first 10 results for portable chargers. 10 of 10 have separate ports for "in" and "out". So it looks like this is a total non-issue.

          Just plug into the port you want, and it will work as you expect.

          If you want to complain that using the same port is a problem, you first need to show that such chargers actually exist.

          • I just went to Amazon and looked at the first 10 results for portable chargers. 10 of 10 have separate ports for "in" and "out". So it looks like this is a total non-issue.

            Can you provide some examples (or maybe even a single example) with one USB-C used ONLY FOR INPUT and one USB-C (out of necessity a different one) that is used ONLY FOR OUTPUT?

            Of course the powerbanks you've found with the old ports which can only be unidirectional have (doh) unidirectional ports! This is not a discussion if you can still

    • by dfm3 ( 830843 )
      All of the power banks I've ever used had two ports, one for charging the battery pack and one for sending power out to the devices that you want charged. Granted, those were all the older style USB; I've never used one with USB-C but I can imagine they work the same way.
      • by Anonymous Coward

        USB-C PD banks use the same port for power input as output, at least the one here on my desk does.

      • Granted, those were all the older style USB; I've never used one with USB-C but I can imagine they work the same way.

        Well your imagination has no influence on the reality (if you don't believe that try to imagine you just won the lottery). Of course your older powerbanks had different ports for "output" and "input", because "before" THERE WAS NO OTHER WAY. However now there's only one (and the same) port. Sure, there could be in theory (and certainly in your imagination) powerbanks that have one USB-C p

        • by dfm3 ( 830843 )
          Well how about that, a few minutes on Amazon and I see you are correct; some of the USB-C banks do use the same port for in/out. That doesn't justify the condescending tone of your post, though.
    • by MachineShedFred ( 621896 ) on Wednesday July 17, 2019 @06:21PM (#58942106) Journal

      The power bank I have allows you to manually "reverse" flow by holding the button down for 5 seconds if it's going the way you don't want.

      https://www.amazon.com/dp/B01L... [amazon.com]

      Turns out this isn't really a problem for a product that anyone thought about for a little bit.

    • by nasch ( 598556 )

      I don't know about laptops, but when connecting two phones that support the feature, you choose on one of them whether to charge the other device. I think if neither device is selected to charge, then no charging occurs.

  • by Anonymous Coward

    The C in USB-C is for complicated.

  • by Anonymous Coward

    Let me help you with that:

    From a blog post:
    Classic USB from the 1.1, 2.0, to 3.0 generations using USB-A and USB-B connectors have a really nice property in that cables were directional and plugs and receptacles were physically distinct to specify a different capability. A USB 3.0 capable USB-B plug was physically larger than a 2.0 plug and would not fit into a USB 2.0-only receptacle. For the end user, this meant that as long as they have a cable that would physically connect to both the host and the devic

  • by Waffle Iron ( 339739 ) on Wednesday July 17, 2019 @03:25PM (#58941210)

    Cables 3-6 are called "Full-Featured Type-C Cables" in the spec,

    I spot an opportunity to avoid confusion in the future: When the next improvement to USB gets deployed, they should name the upgraded cables as "High-Featured Type-C Cables".

    • by Anonymous Coward

      Or High-Featured SuperSpeed Type-C Cables.

      Yo dawg we heard you like dongles...

    • I spot an opportunity to avoid confusion in the future: When the next improvement to USB gets deployed, they should name the upgraded cables as "High-Featured Type-C Cables".

      They'll have their chance with USB4.
      https://en.wikipedia.org/wiki/... [wikipedia.org]

      Or maybe they will go with SuperSpeed for 5Gbps, SuperSpeed+ for 10 Gbps, and SuperSpeed++ for 20Gbps, and SuperSpeed+++ for 40Gbps.
      Or they could just call it what it already is, Thunderbolt 3.
      https://www.pcworld.com/articl... [pcworld.com]

      How many kinds of Thunderbolt cables are there? As I recall only three. Well, four but the fourth kind exist only on paper as best I can tell.

      There's the passive, short length, and 3 amp current rated. There's the

    • Will those be better or worse than the unlimited-featured cables?

  • by Anonymous Coward

    He's talking about USB cables with USB-C connectors. But there are also Firewire 3 cables with USB-C connectors, power cables with USC-C connectors, and DisplayPort cables with USB-C connectors.

    Like most people, the author is confused between USB and USB-C. USB-C is a connector that just happens to be used by some USB cables. But the existence of a USB-C connector on a cable does not mean that it is a USB cable.

    What a mess!

  • by Shotgun ( 30919 ) on Wednesday July 17, 2019 @03:59PM (#58941376)

    If you think this is a problem, try installing an aftermarket radio in a newer car. You have to nearly have a college degree in which randomly numbered connector you need to solder a dozen wires from the radio to will be needed to connect to your car's randomly shaped connector. Once all the splicing is finished, you'll find out that you still need to splice into the car's wiring. And, if you think that sentence is confusing, you should check out the wiring diagram which never tells you how to orient the symmetrical connectors so that you know which is pin 1.

    This is one of those areas where there really should be some regulation. Call it the "Stop Fucking With Us In Silly Ways Act".

    • by Anonymous Coward
      This is completely off topic, but you could just buy that car stereo from a place like Crutchfield, which ships the correct wiring harness for your car/stereo combination. Just plug and go.
    • Never solder your vehicle wiring, the joint is too stiff and will not be reliable.

      For high vibration environments you want to use crimped connectors.

      • re: soldering (Score:4, Informative)

        by King_TJ ( 85913 ) on Wednesday July 17, 2019 @06:13PM (#58942066) Journal

        I know I'm no car stereo installation expert, but I've installed maybe a dozen or so systems over many years. And my experience, going back to the late 1980's with this stuff is that time after time? The problems with loose wires come from crimp connections or wires that pulled loose from spring clip type terminals (typically on power amps) almost every time.

        Yes, a soldered connection is really stiff. But assuming it wasn't a "cold" solder joint (didn't heat the solder up enough, so it dried with a cloudy, dull look instead of a shiny one) - it's also a connection that takes a lot of force to pull loose. You're still presumably going to cover it with heat-shrink tape (or at the very least, electrical tape if you're doing it the lazy/cheap way). So it's got that little bit of rubbery "cushioning" around it to protect from small taps against the vehicle frame from normal vibrations.

        All of the circuits on the boards in your car have their components soldered on, and they seem to survive well enough in the environment.

        I'll always recommend soldering over those 3M red, blue and yellow crimp connectors!

        • In an F1 car (I used to work on an F1 team) wire connections were with mil spec multi pin round connectors. Wire into pins were crimped and soldered. The connector held the pin and the wire on the other side of the solder joint firmly so there is no work hardening where the wire enters the solder joint.

          This was plenty of work, but it worked well.

        • LOL instead of trying to talk down to yourself with beginner talk, just look up what I was talking about on the internet and learn some details. You seem to have not been listening, since your reply pretends I wouldn't know basics, even though I had the knowledge to inform you of the problem with your idea.

          This has nothing to do with cold solder joints. Duh.

          And talking about PCBs that happen to be "in a car" is just whataboutism. Clearly not relevant.

          If you solder over a crimp connection you just took a goo

        • by Alioth ( 221270 )

          The red blue and yellow crimp connectors are actually very reliable (we use them in aviation) - if:

          - you have the proper crimp tool (and a good crimp tool is quite expensive - at least as much as a mid-tier soldering iron), a proper ratchet tool with a properly made die, not the cheap Chinesium things you get for £6 at Halfords
          - you don't get the cheap crap crimp connectors (good ones aren't really that expensive either)
          - the person crimping them knows how to use the crimp tool - which isn't hard, you

        • God there's so much wrong with your post and your approach to this that it's hard where to begin. But I'll try and maybe you can do an even better installation than you think possible.

          The problems with loose wires come from crimp connections

          Holy crap you've crimped it wrong. A decent crimp is orders of magnitude more reliable than a solder joint (I'll get into why in a sec). There's a reason why all car connections are crimped, all aircraft connections, military vehicle connections and industrial connections too. If your crimps can be pulled lose you didn't crimp

      • by Alioth ( 221270 )

        If the connection has proper strain relief and the cables are properly supported, a soldered joint will outlive the car.

        However, crimping is faster and easier and needs a lot less skill to make a good connector. Making a good solder joint and doing all the things to ensure it will last takes a modicum of skill and it also takes time. But you can teach a chimp to crimp. (That's assuming you have the correct crimp tool, and a good one, not a cheap one made from Chinesium).

        • You can't just add strain relief, having good strain relief is an engineering challenge that has to be considered from the very beginning and presents tradeoffs with other uses of space.

          For example, car stereos don't have effective strain relief, you've got a nest of wires, some of which are in a harness, shoved into a small space with a bunch of other wires. You can't control the situation to prevent everything getting wiggled and bumped and twisted.

          In an automotive environment, you don't have control over

          • by Alioth ( 221270 )

            I don't disagree. I think crimping gets a bad rap because people are used to cheap crimp tools and cheap connectors which do a terrible job (which even un-strain-relieved solder joints will actually outlive). People see that a moderately decent crimp tool will set them back £100, so go for the cheap Chinesium non-ratchet one that costs £6, and the connector fails after 3 months because the wire just falls out the improperly crimped connector, so conclude that crimping is rubbish.

            • Exactly! And then they preach it like the Truth on slashdot, without even asking, "is this a 101-level engineering thing with a mainstream, heavily studied answer?" Because yes, yes it is one of those. LOL

              I also think they'd get a perfectly good crimp with a cheap non-ratcheting crimp tool if spent 5 minutes learning how to do it. You need the ratchet to do it all day and have them all be good, but if you're just doing a few crimps on a single car stereo you shouldn't run out of hand power.

              My most expensive

    • ... you should check out the wiring diagram which never tells you how to orient the symmetrical connectors so that you know which is pin 1.

      Having dabbled in electronics over the years, I find that there is almost always some way of identifying pin 1. Either a mark on the connector itself (which may be quite subtle), or a thin stripe on the conductor attached to pin 1,

    • Get a wiring harness adapter for $15 and everything you just cried about is solved in about 20 seconds:

      1. Plug OEM harness into wiring harness adapter.
      2. Use wires coming out of adapter to match up with screw-down terminals on back of head unit.

      Bonus: you didn't just fuck up the OEM wiring and possibly fuck up your solder joints.

      • For the large part, you are correct, but fancy stuff might require more than the stock wiring provides. Head units that incorporate an LCD and act as a DVD player or display feed from a backup camera, will require connections to the reverse light and parking brake.
    • Comment removed based on user account deletion
  • There's a cable that works for every* scenario. Great. Problem solved. Buy those cables and stay away from the crappy ones.

    (Thunderbolt nuances excluded of course)

    • This is exactly what I was thinking - this is a completely solved issue by purchasing one or two $6 cables on Amazon and declaring victory.

      It's annoying that you may not be able to trust whatever cable ships with something to be useful for all cases, but that was the case with USB 1.1 as well - some cheap bastard (phone) manufacturers would ship cables that only had VCC and GND in them because they were only there as a power cable. If you accidentally tried to use it for a regular USB cable you would get n

    • There's a cable that works for every* scenario. Great. Problem solved. Buy those cables and stay away from the crappy ones.

      I'd say two kinds of cables. First being a long, slow, and powerful cable mostly for charging. USB 2 has a length limit of 5 meters while USB 3 allows only for 3 meters, but I don't recall ever seeing a USB3 cable longer than 2 meters. For when speed trumps power, get a shorter USB 3 cable. There's nothing keeping one from getting a 5 amp USB 3 cable instead of one rated for only 3 amps except that they are far more expensive and hard to find.

      (Thunderbolt nuances excluded of course)

      In this case maybe add one more cable to your laptop bag.

      One

  • by thevirtualcat ( 1071504 ) on Wednesday July 17, 2019 @04:05PM (#58941416)

    ... the more they stay the same.

    I remember going through all of my USB Mini-B and Micro-B cables a few years ago and plugging them into a tester. I then proceeded to destroy and discard all the cables that didn't have the data lines and/or couldn't handle at least 1A of current. It made my life a lot less complicated.

    I suspect there will come a time when I have to do the same thing for my USB-C cables.

  • The ones that will stay in for a little while longer, and the ones that immediately fall out. If you are lucky, the problem with the latter ones will be in the plug, so you can just pay for a new cable. Otherwise, you're out of luck unless you have a professional surface mount soldering and desoldering station.
  • by surfcow ( 169572 ) on Wednesday July 17, 2019 @06:13PM (#58942060) Homepage

    The really nice thing about standards in the tech industry
    is that there are so many to choose from.

  • by evil_aaronm ( 671521 ) on Wednesday July 17, 2019 @06:48PM (#58942268)
    So, it's SCSI all over again, with fewer pins?
    • So, it's SCSI all over again, with fewer pins?

      SCSI never went away. The same protocol is going over the various physical layers.

  • I'd just like to point out that a Centronics parallel port had 25 pins. A USB-C 3.2 cable with all the bells and whistles has 24 pins. Yeah yeah, I know, still serial because clocking, but still... this is getting a little ridiculous.

    • But Centronics was faster because it's parallel right?

    • by Alioth ( 221270 )

      Serial and parallel doesn't refer to the amount of signals, but how they are clocked. If you took 16 RS-232 ports and split your data into 16 parts and transmitted them, it would still be serial as each port is independently clocked. With a parallel port there's a single clock for all the signals. Every separate signal (there's 4 of them for USB-C super speed) is independently clocked, so it's not a 4 bit parallel link, but 4 separate serial links.

  • Too Many.
  • USB 3.2 Gen 1 (5gbps) rated at 3A for the Elven-kings under the sky,
    USB 3.2 Gen 1 (5gbps) rated at 5A for the Dwarf-lords in their halls of stone,
    USB 3.2 Gen 2 (10gbps) rated at 3A for Mortal Men doomed to die,
    and USB 3.2 Gen 2 (10gpbs) rated at 5A for the Dark Lord on his dark throne
    In the Land of Mordor where the Shadows lie.
  • by AtomicSymphonic ( 2570041 ) on Thursday July 18, 2019 @01:55AM (#58943988)

    What I personally find hilarious in all this mess is that the electrical and computer engineers involved in the creation and maintenance of this standard **sincerely believe** that this is actually all perfectly reasonable and logical. They're able to tell the difference between a 3A and 5A capable connections and wires. And STILL continue to believe it even after having laypeople point out to them how confusing this standard is.

    Most I have met in my university have honestly given shocked expressions and seem truly bewildered by how confused the mass market is over USB 3.x and USB-C.

    I know Apple was involved in the creation of USB-C, but it feels like they had more of a consulting position in the whole ordeal. They probably weren't in control of how the USB-IF would be rolling out the standard.

    Any EE and CE folks, speak up... Correct me if I'm wrong here, or add in if you wish.

    • What I personally find hilarious in all this mess is that the electrical and computer engineers involved in the creation and maintenance of this standard **sincerely believe** that this is actually all perfectly reasonable and logical.

      When creating a standard to suit multiple needs you need it will result in compromises. The key part here is the CE and EE folks knew up front that this will cause problems which is why that USB standard precisely defines how cables and devices interact specifically to ensure that a clueless consumer (or engineer, you really can't tell the difference between 3A and 5A easily from the outside) can plug in any cable any which direction into any device and it will work at the maximum rate of all components wit

    • What I personally find hilarious in all this mess is that the electrical and computer engineers involved in the creation and maintenance of this standard **sincerely believe** that this is actually all perfectly reasonable and logical. They're able to tell the difference between a 3A and 5A capable connections and wires. And STILL continue to believe it even after having laypeople point out to them how confusing this standard is.

      It is logical once one considers a very important aspect in engineering, and that is cost. They could have defined a standard that required active cables and 5 amp current carrying capacity, but this would have meant every cable was $80. Maybe they could have defined for a shorter passive cable along with this but that still would have made the cable $40. If you want to appease a large portion of the market that don't need up to 40 Gbps and over 60 watts then there needs to be room in the spec to appeal

  • by dohzer ( 867770 )

    hitherto referred to as "USB-C cables"

    ... and then referred to as "USB" cables on the very next line.

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