The Cable Confusion Report

June 4th, 2015

The other day, I just happened to be rummaging through the bunch of cables spread across two bookcases in my home office for something to connect to my Logitech Harmony 900 universal remote. It was one of those USB micro or mini thingies, and I had to unfurl several inter-wrapped cables to find the one that fit. At the other side is the traditional USB A connector, the one that seems always to be inserted upside down the first time you try.

The rest of the cables consist of the usual collection for a long-time Mac user. There were a couple for FireWire 800, a few Ethernet, and other USB styles, plus standard RCA audio cables. I suppose I should sort this mess out someday and get rid of stuff that I no longer use. And I haven’t included the multi-shelf storage cabinet that sits in a shed next to this little home. I haven’t looked in there for years, and no, not because I worry about what’s crawling in there aside from cords and plugs.

Well, yet another cable standard has been foisted on us. Beginning with the controversial 2015 MacBook, and a handful of other computing devices, we now have USB-C, which will add to the confusion, and it may soon get worse.

To be sure, USB-C has one positive aspect aside from an up to 10 gigabit per second performance potential (it’s five gigabits on the MacBook I hear), and that’s a reversible plug, similar to Apple’s Lightning connector. That will forever eliminate the annoyance of almost always inserting a plug in the wrong direction.

Now the other day I read an interview with an official of the USB Implementers Forum explaining how the current USB 3.1 standard can befuddle people. But the confusion is taken with equanimity, as if it’s a perfectly normal thing. So you have the Type-C connector itself. Forgetting the various specs for the protocol, there is the standard USB A cable, the one that is designed to go in one direction. But don’t forget those other USB connectors, the tiny ones used in smartphones, remotes and other gear, the micro and the mini, perennial sources of confusion since you have to look real close at a device to see which one you need.

Well to make matters ever more involved, it appears that the forthcoming Thunderbolt 3 standard, offering twice the bandwidth of Thunderbolt 2, which is in use on most Macs nowadays (except for a certain MacBook), will use a USB-C style cable. What this means is that you may end up connecting the right connector to the wrong peripheral once Thunderbolt 3 gear is available.

Don’t even ask me to explain how this can become ever more convoluted than the current USB plug configuration mess. But in case you’re wondering, both Thunderbolt and Thunderbolt 2 use a Mini DisplayPort cable, same as you’d use to attach external displays that support that standard. Otherwise, get an adapter.

I can see the value of simplicity, although it will take a while for the situation to sort itself out. PC makers, for example, haven’t been too keen on Thunderbolt which, as with FireWire, is often perceived as an Apple standard, even though the developers of the interface include Intel.

What would probably happen is that, when Thunderbolt 3 is available, there will be more of them to replace existing USB ports, thus allowing you to connect most any peripheral with the proper adapter. I suppose there might be one or more traditional USB A ports as well to avoid an adapter mess, though probably not on Macs since Apple will invariably want to offer the latest and greatest technology.

Support for Thunderbolt 3 is incorporated into the forthcoming Intel Skylake processors, which are due later this year. That may ultimately simplify matters of handling the multiple connection schemes. Cheap PCs will stick with USB-C or a legacy USB port. Costlier PCs, such as Macs, will switch to multiple Thunderbolt 3 ports to handle everything, and that includes FireWire. The port’s intelligence will figure out what you’ve connected to it and provide the appropriate support. So the benefit would be an all-in-one connection scheme for mid-priced and high-end PCs that, over time, might eventually eliminate multiple sources of confusion.

Except when you take a Thunderbolt 3 peripheral and attempt to connect it to a port that only supports USB-C. Simplicity has its problems, and this will likely be yet another source of technical support calls.

Of course all this might be academic in a few years, when everything, or most things, are wireless. That would certainly cater to Apple’s minimalist tastes, and the dream that a portable computing device wouldn’t have to make a physical connection to connect to anything.

Until then, expect just more confusion when you have to sort out that mass of cables on a shelf somewhere.

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4 Responses to “The Cable Confusion Report”

  1. DFS says:

    “Of course all this might be academic in a few years, when everything, or most things, are wireless. ” This of course doesn’t apply to cables that deliver power. When I’m on the road I’m always unhappy about the number of cables I have to take along to recharge my various devices. Thunderbolt has its strong points and I’m extremely grateful to have it so I can keep on using my old iMac as an external monitor. But it sure would simplify my life if I could recharge all my devices using a single micro USB cable.

  2. Mr. Smith says:

    It is true that the many variations of USB-C connector and cable capabilities will probably be a new source of confusion, there is no doubt.
    If there’s a little Thunderbolt logo next to a USB-C connector, and you use a cable with a Thunderbolt logo and USB-C connectors, then you’re using Thunderbolt 3 and it should Just Work(1). That’s the good news.

    “both Thunderbolt and Thunderbolt 2 use a Mini DisplayPort cable”
    no, they both use a mini DisplayPort *connector*, but a Thunderbolt *cable*. You can use a mini DisplayPort cable, but the only thing you’ll successfully connect to that Thunderbolt port with a DisplayPort cable is a display.

    “Support for Thunderbolt 3 is incorporated into the forthcoming Intel Skylake processors”
    no, it is in the Alpine Ridge Thunderbolt controller.

    “Costlier PCs, such as Macs, will switch to multiple Thunderbolt 3 ports to handle everything, and that includes FireWire.”
    no version of Thunderbolt tunnels FireWire. FireWire is available by putting a FireWire controller at the end of the PCIe bus which is tunneled out of the host by the Thunderbolt connection. That hasn’t changed with Thunderbolt 3;
    Thunderbolt 3 adds native support for USB 3.1 Gen 2 (the 10Gbps flavor of USB). So if you plug a USB device of any speed into a Thunderbolt 3 host controller’s USB-C port, it will work.

    In most cases, if you plug in an incompatible device, or use the wrong cable, the device or the cable will provide enough information to the host to allow it to tell you what you need to do.

    For more information, look here:

    (1) Just Work: at 20Gbps or 40Gbps, depending on whether the Thunderbolt cable is active or passive.

    • @Mr. Smith, So there’s no confusion. When I set up an iMac with Retina 5K display, I used a FireWire 800 to Thunderbolt connector for my backup drives. So the hardware did have FireWire support using the Thunderbolt 2 port.

      As far as the differences between cables and connectors are concerned, most people don’t notice the fine details of the cable. Just the connector.


  3. Kaleberg says:

    It sounds like things are moving in a good direction. In five or ten years all connectors will be USB-C, and all connections will be on a “best effort” basis. The transfer speed will depend on negotiations between the units at either end of the cable. I’m sure there will be problems with out of date drivers resulting in slower speeds now and then, but that’s a problem we have now. If nothing else, it means there will only be one cable type to stock and lug around.

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