Less than a week after announcing the USB 3.2 spec, the USB Implementers Forums (USB-IF) has announced the spec for the USB 4 protocol, or “USB4,” as it might be known upon release.
The protocol seemed to be modeled after the Thunderbolt protocol.
The group offered the following description of what to expect:
“The USB Promoter Group today announced the pending release of the USB4 specification, a major update to deliver the next generation USB architecture that compliments and builds on the existing USB 3.2 and USB 2.0 architectures. The USB4 architecture is based on the Thunderbolt protocol specification recently contributed by Intel Corporation. It doubles the bandwidth of USB and enables multiple simultaneous data and display protocols […]”
Even as the USB4 specification introduces a new underlying protocol, compatibility with existing USB 3.2, USB 2.0 and Thunderbolt 3 hosts and devices is supported; the resulting connection scales to the best mutual capability of the devices being connected.
Some of the bullet points include dual-lane operation, 40Gbps effective speed, and backwards compatibility with USB 2.0, USB 3.0, and Thunderbolt 3 devices. As such, all Thunderbolt 3 cables should still work with USB4 upon its release.
It’s also thought that the backwards compatibility with Thunderbolt 3 should offer USB4 the same power delivery options.
The announcement is currently in draft form, and a final spec set is set to be confirmed for the middle of this year. Still, given the compatibility statement, it seems unlikely that anything significant will change between now and then.
USB 3.2 will appear in devices later this year, offering dual-lane bandwidth totaling 20Gbps for the full-fat version.
It’s also been noted that it’s expected to take 18 months between the final spec being published in the second half of this year, and the first devices hitting the market, so those shouldn’t be expected until sometime in 2021.
Stay tuned for additional details as they become available.