USB4 eats Thunderbolt 3 for the 40 Gbps super-cable in 2021

The USB Implementers Forum has had a busy week. At the tail end of February, it seemed to go to great lengths to make USB 3.2 as confusing as humanly possible, and today, it announced the upcoming release of the USB4 specification. At the moment, we've only got a draft specification for USB4, with the final spec to be delivered in the middle of 2019.

Still, even though we're in the early days of USB4, we know enough to say that it will be bringing Thunderbolt 3 capabilities to the masses. Intel released the Thunderbolt 3 specification royalty-free back in 2017, and the USB Promoter Group is implementing that specification in USB4. That means we can expect two-lane operation with data transfer speeds of up to 40 Gbps, which is twice what USB 3.2 boasts.

The USB Promoter Group says that USB4 will be backward compatible with previous iterations, including USB 3.2, Thunderbolt 3, and USB 2.0. It'll have a lot of the same functionality as Thunderbolt 3 as well, including simultaneous data and display delivery: "As the USB Type-C connector has evolved into the role as the external display port of many host products, the USB4 specification provides the host the ability to optimally scale allocations for display data flow," the USB Operator Group said today.

So, for anyone who has been using Thunderbolt 3 regularly for the past few years, the announcement of USB4 probably isn't all that exciting. Its eventual roll out does mean that Thunderbolt 3 adoption should become much more widespread in a relatively short amount of time, though, which will definitely be nice to see.

As The Verge points out, the USB-IF expects manufacturers to take around 18 months to start producing USB4 devices once the specification is finalized. Since that won't happen until mid-2019, that means USB4 probably won't arrive in a significant way until 2021. We've got a while to wait before USB4 is here, but while we wait, we'll be keeping an eye out for more information. Stay tuned.