USB-C Is A Mess, Here's How To Navigate It

USB Type-C, or simply USB-C, sounds fine in theory — a single port to handle charging, data transfer, video output, and more, and one that's reversible too. Three years down the line from its introduction, you'll find it on most smartphones and many laptops, but its apparent simplicity isn't the whole story. Here's what you need to know about USB-C in 2018.

What is USB-C?

The whole purpose of USB in general is to standardize ports and connectors, and make sure one bit of kit works with another. The clue's in the name: Universal Serial Bus. USB-C is the latest physical implementation of that, and aims to make life simpler than ever for consumers and manufacturers alike.

Specifically, USB-C refers to the connector type at the end of a cable or embedded in the side of a laptop — it's that compact little plug that you can (at last!) slot in either way up. It doesn't refer to the actual USB standard supported by a cable or port, but its physical shape and the technology and wiring that can be built in.

As we've mentioned, this connector can technically support data transfer, charging, video output (technically known as Alternate Mode), and more. It can also be used bi-directionally (so you can charge your phone from your laptop, if you want).

Whether or not these features are available depends not just on USB-C but also the USB standard of your devices, with the latest being USB 3.2 (though it hasn't actually come to any hardware yet). In other words, a USB-C socket could support USB 2.0, USB 3.1, or even Thunderbolt.

These underlying USB standards, as well as connector types like USB-C, are developed by the USB Implementers Forum (USB-IF). New plugs and new USB technology are often revealed at the same time, which can be confusing, but they're technically separate — it's the version of USB, as well as the physical shape and configuration of the port, that determines what you can do with your smartphone or your laptop.

Current USB and USB-C standards

USB 3.2 has a theoretical data transfer rate of 20 Gbps, up from the 10 Gbps offered by USB 3.1, though you're unlikely to get up to those speeds on standard consumer gear. Not much else has changed with the upgrade, hence the smaller 0.1 number bump, but USB 3.2 devices won't be with us until sometime in 2019.

As for the accompanying USB-C standard, that's not been changed since its introduction. What you might not realise is that manufacturers and cable makers have a choice for how to implement USB-C and which features to include — so for example, your laptop might have four USB-C ports, but only one can be used to charge it. Add in dongles, and it just gets more complicated.

Working out what USB-C actually means on a spec sheet can be tricky. If you need a cable that does charging on bigger devices, or video output, you need to read through the whole description besides just looking at the connector type — so this cable won't run an external display over USB-C for you, but this cable will. The difference is apparent when you check the whole listing, but you need to know what you're looking out for.

If you look at the tech specs for the Pixel 2, you'll see USB-C listed alongside the USB version (3.1) and the separate Power Delivery 2.0 standard for faster charging (which again is closely related to, but technically separate from, USB-C). What the Pixel 2 doesn't have is USB-C video out capabilities — maybe not something you need from your smartphone, but it emphasises the point that there's more to a port than the connector shape.

The problems with USB-C

As we've noted above, seeing a USB-C port on the bottom of your phone or the side of your laptop only tells you part of the story: Not all USB-C sockets are created equal. What you can actual do with it depends on the tech built into the cables you're using, and the tech the manufacturer has decided to build into the port.

Robert Triggs very eloquently lays out the situation over at Android Authority, pointing out that the different ways phone makers are using USB-C is taking some of the shine off this supposedly brave new world of one socket to rule them all.

For example: Having a USB-C port on your phone means you can use any USB-C charger right? Well, yes ... up to a point, but you might not get the charging speeds or bi-directional charging you were looking for.

In other words, USB-C hasn't quite solved all our dongle and cable problems yet. It's an exciting new standard, but its versatility means it's expensive and complicated to implement, which is why some USB-C ports and cables might cut out a number of advanced features associated with the standard. Add in company's proprietary tech too (like fast charging) and it gets harder to get clarity.

Video output is the same: The extra capabilities of USB-C mean high-speed data can be hit by interference, and to minimise this problem the carrying cable needs some extra technology built in, especially at longer lengths (above a meter or so). You need to look out for active rather than passive cabling, and/or the SuperSpeed logo, and of course make sure video output is supported by the source USB-C port in the first place.

Using USB-C now and in the future

Despite the issues we've mentioned, there's no doubt USB-C is the future, and in many ways a vast improvement on what's gone before. Underlying USB standards will continue to improve and develop with the same connector type, starting with the USB 3.2 enhancements that are coming next year.

For the time being, you need to be extra careful when buying something with USB-C ports — or more specifically, buying something else to work with something with USB-C ports. Spec sheets should list the power, data transfer, and other standards that are supported, but many manufacturers are lazy in this regard, and you'll often have to resort to digging around forums and product reviews, or contacting the manufacturer directly.

The situation will get better as newer hardware arrives and the need to support legacy devices drops off — if you're buying all-new USB-C devices, you don't have too panic too much about them not working together. As prices come down, more devices hit the market, and components improve, more and more USB-C ports will be able to do everything a USB-C port should.

In the meantime, better product labels and clearer specs listings would certainly help users avoid any potential USB-C pitfalls, especially when setting up accessories and extra devices that don't come bundled in the box. Until that happens be super cautious whenever you buy cables and devices. Double and triple check that the cables and ports you're using can actually do what you want them to do.


Comments

    This article makes it more confusing than it needs to be. USB-C is just a connector type, nothing more. It's no different to USB-A, B, A-mini, B-mini. They're just connectors, they're not dependent on protocol.

    All USB cables support up to a certain USB protocol version, regardless of their connector. Some support USB 2.0, some support USB 3.0. Because of when USB-C was added, all USB-C cables support USB 3.1.

    Ports, regardless of what connector they use, support whatever protocol the hardware allows. The connector and protocol can mix-and-match - you can have a USB-C 2.0 port just the same as a USB-A 2.0 port. You can have a USB-A 3.1 port just the same as a USB-C 3.1 port. The protocol and connector aren't dependent on each other.

    It's basically that simple. USB-C cables support 3.1 and earlier, but the features that can travel across that cable are down to the lowest protocol version the hardware on both ends support.

      It's still a mess. All Type-C Cables AND Ports should be able to do all the things.
      I've been hoping and looking for a good Type-C laptop dock with dual video out but it seems impossible.

        If your device supports Thunderbolt, maybe check out Lenovo's Thunderbolt dock? It'll also charge your laptop if it supports charging over USB-C.

        There's no port out there (I mean any port, not just USB) that can just 'do all things', the port is also the hardware tied to the USB protocol version and hardware capabilities change over iterations. If the port doesn't support USB-PD then it probably isn't wired to take more than 5V off the motherboard. This is no different to the fact 100Mbps ethernet ports can't just 'do' 1Gbps, because they lack the physical hardware necessary to do it.

        Dual video out USB-C laptop docks exist. Whether they're good is a matter of personal opinion of course, but it's not because of a limitation or confusion of the technology. The two things are cleanly delineated, it's articles like this that confuse the two.

        (Wanted to edit to add this and got Kotaku's famous 'fuck you', so I've had to repost the whole thing: James does point out alt mode DisplayPort or Thunderbolt currently requires USB-C, not just any USB 3.1 cable. I forgot about it in my first post and it's basically the exception to the rule, everything else about USB 3.1 runs over any connector.)

          I've been looking at a lot of docks and most only have on video out or do mirrored displays. The few that advertise dual video out either have 1 star reviews or cost $400.

          Also, yes, Kotaku's "Your signed in enough to start a comment, but not submit it" is absolutely infuriating.

            It's not an area I know very well, but I thought this Targus dock seems okay. The one star review looks like it's about compatibility with a specific device, but it also has a five star review as well. It is on the expensive side too.

            I'm generally disappointed with how slow 3.1 and USB-C adoption is in general, it's still really difficult to find motherboards that offer more than token support for the latter.

              Other, smaller issues pop up as well. Bought a new Samsung S9 a couple of months back, which basically makes 95% of the cables in my place obsolete.

              But I want a second cable for work, in case I forget to charge it. With no other cable being USB-C, it means buying another just for that purpose. Which is annoying. First world problem for sure, but still annoying.

              Older devices all share similar enough cables that I can have 2 or 3 both at home and work, but the slow adoption means the S9 was the first USB-C device I've bought. Old phone (HTC M8) shared a cable with my PS4 controller for example.

              It'll change over time, but man its a slow process this time around.

                Did the S9 not come with a USB-C adaptor as well as the cable? My S8 came with one of these so you'd still be able to use your older cables. The PD rate is limited if you use an older cable, of course, but at least it gave the option.

                I get the frustration at changing cables. At least the standard is backwards-compatible so you can get an A-to-C USB cable and still plug it in to your PC or whatever else.

                  Apparently that link downloads the picture instead of just linking to it. No idea why, sorry about that.

                  Dont remember seeing it, but its possible I missed it. It could charge at USB 1.0 and it would be enough. Got a couple of cheap adaptors online, so will see how they go. I dont mind having spares anyhow.

              Dock looks like what I'd be needing, but convincing the finance guy to get 8+ of them is going to be a tough sell indeed. Meanwhile older laptops have HDMI + VGA and dual output built in

      The Amazon Basics cable linked in the article has USB-C connectors, yet only supports USB 2.0 speeds. I suspect the reason for this is that USB 2.0 signals use different wires than higher speed USB 3.0 signals on the type-C connector, and that Amazon cable only connects the USB 2.0 pins on its two plugs. It'd be nice if people didn't build cables like this, but there's going to be a market for cheap cables like this.

      The alternative modes (for DisplayPort, Thunderbolt, etc) are likely restricted to USB-C too, since that connector adds two extra SuperSpeed differential pairs on top of those found in the USB 3 variants of the -A and -B connectors.

        Original got trapped in edit moderation. Reposted:

        I stand corrected, when I last read the USB-C specification I was sure it guaranteed that compliant USB-C cables supported version 3.1 minimum.

        There are USB 3.1g2 standard-A cables that support the full 10Gbps. While they don't support alt mode directly by wire I don't see a reason they couldn't support it through multiplexing. It'd only need a firmware update, the hardware already allows it.

        It does look like USB 3.2 is moving to USB-C only for its core features though, what with its 20Gbps requiring 3.1g2+ certified USB-C cables.

          Now that I think on it and don't want to tempt moderation again, alt mode isn't part of the 3.1 standard, it's specifically a USB-C cable feature. A vendor could attach a Thunderbolt alt mode to a USB-C 2.0 port if they wanted.

            sure, but they'd need to make sure they implement all the configuration channel protocols. My main point was that USB-C is not simply a new form factor for the same protocols like mini-USB/micro-USB were. Most obviously, the extra data channels.

            Also, looking at the Wikipedia page, it sounds like the Amazon cable probably has all wires on the connectors connected, but doesn't shield SuperSpeed pairs, and may wire the four power contacts together.

              You're right, it's not 'just' a new form factor. What I was trying to convey in my original post is that it's purely cable-side and has nothing to do with the hardware version. USB-C doesn't guarantee any particular features, it's just a connector.

              I maintain it's still a simple arrangement though, you just find what version/features your port supports, then use a cable that supports the same features. Except for alt mode which I admit I'd forgotten about, simply matching protocol versions is all you need.

                It's also complicated by the amount of non-compliant gear out there. This can be a real problem when USB Power Delivery means you might be sending up to 100 W over the cable: if the cables or devices get the negotiation wrong, there's a good possibility that you could fry the device on the other end.

                Last year, a Google engineer was buying cables and chargers, testing them, and then writing up reviews here: https://plus.google.com/collection/s0Inv -- he found a number of broken adapter cables, faulty chargers, etc, and managed to burn out the charging circuits on his laptop once.

                Even big companies like Nintendo have gotten this wrong, e.g. making the Switch unreliable when running with a compliant third party USB-PD charger.

                  Even the best designed protocol and cable standards can't really do much if manufacturers don't follow those standards, unfortunately. I don't really understand why Nintendo would have had a problem with it, USB-PD isn't a complicated standard even at a technical level.

                  @zombiejesus: the Switch is probably more complicated than most devices though: both the tablet and dock support USB-C power delivery, with the dock acting as a sink (for the power adapter), and source (for the tablet). It also draws some power itself, so can't pass through the PD messages unchanged. It correctly subtracts its power usage for some profiles, but not others.

                  It also implements a proprietary "Nintendo" alternative mode. That isn't necessarily a bad thing, but the dock will enter the mode without first negotiating it.

                  In the end, you've got a device that is built on industry standard protocols, but only works reliably with first party kit. This post has some more details:

                  https://plus.google.com/102612254593917101378/posts/2CUPZ5yVTRT

      The amazon listing in the article for the cable that doesn't support the full features specifically states that the USB-C to USB-C cable only supports protocol 2.0 and will transfer data at 480mbps.

      When stuff with Amazon branding (not just dodgy Chinese ones from nobody manufacturers) is pulling this kind of shit, there's no way you can afford to be so simplistic about it.

        Nevermind. I should've read the entire thread.

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