Sorting out the USB 3, USB 4, Thunderbolt, USB-C mess

With the varieties of USB and Thunderbolt terminology floating about, as well as new versions on the horizon, sorting out the mess can be a problem. AppleInsider‘s Malcolm Owen covers what you need to know about USB 3, USB 4, USB-C, Thunderbolt 3, and Thunderbolt 4.

USB-C connector
USB-C connector (male)

Malcolm Owen for AppleInsider:

If you don’t read any further, here’s your main takeaway: The term “USB-C” by itself doesn’t specify anything for data, charging, or video beyond the physicality of the connector. But, as you might expect, there are a lot of details behind USB 3, USB 4, Thunderbolt 3, Thunderbolt 4, and how they pertain to the USB-C connector.

Launched in 2020, Thunderbolt 4 is Intel’s move to improve upon the groundwork of Thunderbolt 3. Unlike the shift from Thunderbolt 2 to Thunderbolt 3, there’s no change to the 40Gbps throughput Thunderbolt 4 will provide, but the way it does so will be improved.

For a start, the standard will increase the minimum video and data requirements from what was demanded for Thunderbolt 3 certification. Rather than supporting one 4K display, a Thunderbolt 4 device must be able to handle at least two 4K displays or one 8K screen, while the PCIe support for storage must be able to support 32Gbps transfers, up from 16Gbps.

Thunderbolt 4 will also include support for docks with up to four Thunderbolt 4 ports, with the bonus of the ability to wake a computer by touching the keyboard or mouse, when both the peripherals and the computer are connected to the dock.

MacDailyNews Take: Anyone who has, for example, a 16-inch MacBook Pro and two 4K displays (which is what our setups look like today) knows that what we really want is a simple box (or two) that connects to one (or two) of our four Thunderbolt 3 (USB-C) ports and gives us multiple Thunderbolt 3 (USB-C) ports. We don’t want Swiss army knife docks with antiquated card readers and USB Type-A ports and other assorted (forever unused) crap. So, we welcome Thunderbolt 4 even though, we’ll need new Macs (but, we will anyway with the upgrade to Apple silicon). Note: Apple Silicon Macs will continue to support Thunderbolt.


  1. Intel just likes to make things pointlessly complicated so that people have to buy adaptors and overestimate what a given device can actually do. Also, being complicated exhausts consumers and prevents them from looking at other alternatives. I’m not sure Apple is innocent of this either.

    I remember being so excited about the Lightning/Thunderbolt combo when they first came out. I’m tired of being disappointed.

    1. That’s right. Maybe they are changing the specification to allow twice as much of the data path to be reserved for video. Or maybe they are building data compression into the system?

  2. Don’t know about y’all but I won’t be changing out my 2019 Mac Pro anytime soon to an ARM version. It adds insult to injury Apple manhandled the whole Mac Pro situation for so long that by the time they did issue a new machine it starts to butt up against the next CPU generation. Nice.

  3. For the average user all they need to know is that the same connector can be used for multiple devices. This is what is good about USB-C. Plus there is no upside down for this cable just like the Lightning cable.

    For high end applications, the users are generally knowledgeable enough to know what they need. I think is it great that USB-C and TB 3 uses the same connector. TB 3/4 cables are really only needed for video and data transfer and it is likely that one would have a dedicated cable for each peripheral. For anything else such as general charging / data transfer, the basic USB-C cable will be sufficient.

    Hopefully Apple will switch the iPhones to USB-C. Then for wired charge and transfer we only need to have one cable type. I now have a GaN charger that is a quarter of the size of the Apple version that I can use for any Apple device (if wireless charging is not available).

    1. Only annoying thing about the USB-C connector is, seemingly, not all are built equally. I have cables that come with drives that are too loose connected to my Mac while other cables fit snugly. Not ideal if a drive is used as a Time Machine.

  4. serious question:

    Will a usb-c to display port cable connected to a 4k monitor and my 2002 iMac give me full 4k resolution and sound or do I need a much more expensive thunderbolt 3 to display port cable?

    Same question but with HDMI.

    Will a usb-c to HMDI give me full 4k? Or do I need a tb3 to HMDI?

    I’m talking here about a non-thunderbolt 4k monitor.

      1. You need Thunderbolt, basically. It comes down to quality control and shielding for cutting down on signal crosstalk. Since ‘USB-C’ refers only to the connector and not speed capability, A USB-C cable can be accurately labeled might mean the cables but only be capable of as little as 480 Mbps operation. A thunderbolt 3 cable on the other hand is always designed for 40 Gbps operation.

  5. Just plug it in and it works.
    Nice goal, but a utility app should be included with your Mac to identify/confirm how fast and what protocol your USB/Thunderbolt cords are communicating with your Mac.

  6. Yes, its a mess.

    Its a mess largely brought about because someone thought it would be a wonderful idea to force the convergence of video with data, resulting in a “Jack of All Trades, Yet Master of None” compromise.

    Well, its not a wonderful idea.

    And this “..but ONE cable!..” is BS too:
    Because when you have 2 peripherals, you still need 2 cables. And 3 for 3, etc.

    Only now the damn things are $50 each, so you’re never going to have spares laying around. Another aspect of this profoundly consumer-unfriendly product design decision.

    The only party who’s had any benefit out of this has been the PC manufacturers who minimize the number of ports on their laptops.

    Lets resolve to update the standards one more time, and dedicate the plugs.


    I think everyone can figure out which one’s for Video & which is for Data.

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