USB-C

In Q4 2013 the USB 3.0 Promoter Group, a consortium of technology companies including HP, Intel, and Microsoft, announced that they were developing a single connector designed to replace all existing ports found on consumer devices. The new connection was motivated by the desire to simplify wired connectivity and the demand for thinner devices. Up to that point, the sides of most laptops were covered with a variety of ports enabling data transfer, video output, and power delivery, with many competing standards providing similar functionality in slightly different form, factors, and combinations. Some of the most enduring artifacts of the past several decades of consumer electronics development are tangled collections of cables and adapters, often maintained by consumers long after their respective devices have been retired. USB-C proposed to collapse this mess of connectors into a single port roughly the size of the USB Micro-B plug found on many smartphones. Unlike previous USB cables, which paired a standard host connector with a variety of peripheral connector types, the new cables feature the same plug on either end, with redundant wiring and a symmetrical design that allow the cables to be connected in either possible orientation. The new standard introduced a single port philosophy: in the future, unique ports for specific functions and different classes of devices could be replaced with a single port shared across all devices and accommodating every function.

The cable, and several devices featuring the new port, made their debut at the 2015 CES (formerly the Consumer Electronics Show) to generally enthusiastic reviews. Tech bloggers celebrated the end of the so-called “superposition” issue (the tendency for it to take three attempts to figure out the correct orientation to plug in a USB cable) and the allure of a single-cable future. But alongside the promise of streamlined connectivity came the immediate practical consequences following any attempt to replace a widely adopted standard. The new design provides an improved platform for future development, but it also transforms otherwise current devices into legacy tech. USB’s previous versions maintained basic compatibility across generations, but with the introduction of USB-C all existing USB devices now require adapters to work with the new standard. A significant segment of the global population relies on mobile devices for Internet access; USB-C deprecates the conventional USB port at the very moment it is beginning to be incorporated into public infrastructure that has a much longer expected life span than consumer electronics—buildings, subway cars, urban information kiosks—to accommodate these users’ needs.

One of the most publicized issues accompanying USB-C’s release was the prevalence of uncertified cables. For a time, the most reliable way to purchase a cable online was to consult a public spreadsheet produced by Google engineer Benson Leung, who took it upon himself to independently review cables available on Amazon after he grew frustrated with the number of out-of-spec cables for sale. Leung ended up frying his computer in the testing process when an improperly wired USB-C to USB-A cable allowed his laptop to draw too much power from the computer’s USB-A port. The possibility of damage caused by faulty cables is not unique to USB-C, but there is an increased risk when using faulty adapter cables with old devices because the power delivery protocol USB-C supports allows for a much greater throughput (up to 100 watts) than past devices could handle (USB 2.0 supported a maximum of 2.5 watts).

USB-C went mainstream with the release of Apple’s MacBook laptop in 2015. Its design eliminated all ports except for a single USB-C port and a 3.5mm audio jack. The laptop provided an ideal showcase for USB-C’s capabilities by forcing video output, charging, and data transfer all to make use of the same port, but verged on user hostility in its dogmatism. The irony of a port designed to simplify connectivity in practice leading to adopters needing to carry a host of adapters to connect to devices they used to be able to plug directly into their computers, gave rise to “dongle life” memes.

Apple has a history of aggressive moves intended to accelerate the transition away from old standards—the company was among the first to eliminate physical media drives from their mobile computers, and it more recently faced criticism for the removal of the audio jack from its smart phones—but the abrupt shift to USB-C produced a contradiction in philosophy between two of their major product lines. Apple’s laptop computers obstinately push a single port standard, while their smart phones still make use of a proprietary connector. Although the flagship phones from all major Android manufacturers have adopted USB-C, the large market for “Made for iPhone” accessories, and the considerable revenue stream Apple receives for licensing and certifying these devices, provide a strong disincentive preventing them from following suit. USB is not an open source platform, either—the $5,000 vendor ID and $3,500 certification fees can be prohibitive for small-run products—but these fees are paid to a nonprofit organization and pale in comparison to the rumored fees for Apple’s MFi program (exact numbers are available only under a nondisclosure agreement, but they have been rumored to be as high as $4 per device or greater). Full adoption of the USB-C standard would infringe on a significant revenue stream and probably also result in backlash from consumers who have purchased Lightning connector accessories. Orthodox conformance with the USB-C standard would have clear drawbacks and no inherent performance improvements, apart from the conceptual clarity achieved by acquiescing to an arbitrary standard. With the release of iPhone 8, Apple introduced USB-C to Lightning adapter cables—a compromise that arguably undermines USB-C’s design intent but is probably preferable for most existing users. The cable is not included with the phone, but the purchase of this otherwise superfluous accessory is incentivized because it is required in order to take full advantage of the new phones’ fast-charging capability.

Although much of its appeal banks on the simplicity of a universal cable, USB-C is a connector design, not a data transfer specification. Accordingly, cables and ports essentially identical in appearance can deliver vastly different performance. One of the first USB-C devices released, the Nokia N1 tablet, used the older USB 2.0 specification, which supports a maximum data transfer rate far less than that of the most current standard, USB 3.1. Although a similar issue was present with past generations of USB devices, it was the result of incremental performance improvements that maintained backward compatibility. Despite breaking continuity with previous versions, the presence of a USB-C port does not guarantee support for the latest data transfer specifications.

USB-C’s capacity to replace all other ports on consumer devices is realized through its support for alternate modes, which enables certain pins to transmit non-USB data. However, this provision, which facilitates USB-C’s most ambitious objective, also undermines what, historically, was USB’s greatest virtue: it’s cross compatibility. In the past, if the plugs fit, the devices should work together. USB-C’s support for various protocols across the same connector means this presumption no longer applies. For many years, FireWire was the main alternative to USB. Its successor, Thunderbolt, has been developed by Intel with input from Apple. Over past implementations, Thunderbolt piggybacked on the Mini DisplayPort found on Mac laptops that was originally introduced as an audiovisual interface. After Apple ditched all other ports on its new laptops in favor of USB-C, Intel announced that the upcoming iteration of the interface, Thunderbolt 3, would also transition to the USB-C connectors. On the surface, it is a coup for the USB-designed port to be adopted by its historical competitor, but the tradeoff for the concrete performance upgrades Thunderbolt 3 provides is a loss of compatibility across the USB-C port standard. USB-C devices remain compatible with Thunderbolt 3 ports, but Thunderbolt 3 devices do not work with standard USB-C interfaces despite sharing the same port design. “Full featured” USB-C cables provide basic Thunderbolt functionality, but the interface requires special “Active” USB-C cables to achieve full performance, and lower-specification cables may not work at all. Instead of delivering a single cable future, USB-C’s flexibility has produced a situation wherein physical compatibility is no longer a guarantee of functionality, trading the minor inconvenience of multiple, but clearly identifiable, ports for the illusory elegance of a single port with murky compatibility.

Early adopters of USB-C have been subjected to an immediately diminished experience for the promise of forthcoming benefits. Although USB-C’s design has several clear advantages over its predecessor, the most significant advantages will be realized only after full adoption. Considerable hurdles stand in the way of this idealized implementation, including overcoming widely adopted standards and replacing existing hardware, quality control, competition with proprietary ports, and complicated compatibility issues. Heterodox implementations have resulted in the introduction of a variety of adapter cables—a state of affairs not much different from the situation USB-C sought to improve. Other implementations result in devices that share seemingly identical ports but will not necessarily work with each other, or will work with some cables and not others, which is actually more confusing and frustrating than the present situation. The simplest remedy for this situation would be to require all USB-C devices and cables be made to the highest specifications, but doing so would result in unnecessary expenses that have no impact on most devices’ performance. Meanwhile, smart phones and tablets—which, to hear many manufacturers tell it will soon make conventional computers niche items (Apple’s maligned “what’s a computer?” ad)—are moving toward fully wireless functionality. With wireless charging and data transfer, it is conceivable that many new devices will never need to connect to a physical port.