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.
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.
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 realize 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 emphasizes the point that there’s more to a port than the connector shape.
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 actually 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 minimize 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.
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.