As our devices get smarter and faster, we need new connectors to keep them all working smoothly together. Darien Graham-Smith examines the ports and technologies you might see on your next computer – or the one after that

Next-gen USB/Thunderbolt

You can’t talk about the future of USB without talking about Thunderbolt, and vice versa. Although these two general-purpose interconnects were originally completely separate, with different plugs and cables, the latest Thunderbolt standards are supersets of USB, and operate over the same physical sockets.

What that means in practice is that while the USB-C ports on your laptop will definitely support USB peripherals, they might (or might not) also support Thunderbolt – as long as you’re connecting a Thunderbolt-compatible device with a Thunderbolt-compatible cable. This somewhat confusing situation won’t going to change in the foreseeable future, because right now no future versions of USB or Thunderbolt have been announced. That doesn’t mean we won’t see any movement, though: few devices are up to date with the latest standards, so the evolution in the next few years will be all about widespread adoption.

On the USB front, the name of the game is USB4. (Note that that’s not USB 4 or USB 4.0, but USB4 with no space – the USB-IF just can’t help fiddling with the branding.) USB4 was actually launched, with zero fanfare, in 2019; you might even already be using it without realising it, as it’s built into most recent Apple computers, along with a number of high-end AMD and Intel motherboards.

USB4 uses the same USB-C connectors and cables as previous USB 3 devices, and supports all the same transfer modes, up to 20Gbits/sec. In addition, it enables a new 40Gbits/sec mode for compatible devices, along with the ability to “tunnel” PCIe connections over a USB link – providing a simpler way to attach external devices such as NVMe SSDs.

In 2022, USB4 v2.0 brought even bigger bandwidth benefits: USB4 v2.0 devices can take advantage of an ultra-high-speed 80Gbits/sec connection mode, or a new asymmetric mode supporting 120Gbits/sec upstream and 40Gbits/sec down – ideal for driving multiple high-resolution monitors over one cable.

Meanwhile, Apple has recently started to roll out its first machines equipped with Thunderbolt 5. Still running over a USB-C connection, this raises the available connection speeds to match those of USB4 v2.0. In fact, now that USB4 supports ultra-fast connections and PCIe tunnelling, there’s very little advantage to using Thunderbolt, except in terms of device support: most of the fastest external SSDs on the market currently use Thunderbolt 5.