USB Doubles the Performance of USB4 with Version 2.0
The USB Promoter Group has announced that it has developed a new version of USB4, which it is calling Version 2.0. It allows up to 80Gbps of data transmission over existing USB-C connectors and cables compared to 40Gbps for USB4 Version 1. At the moment, this is just a specification announcement, and it will take some time for products to be designed and implemented, but this is a significant improvement. The USB group seems to have been able to do this by changing how the USB physical layer works, which will mean new interface chips. Don’t expect to see products (other than cables) any time soon with the new rating.
Now, 80Gbps is tantalizing because you should be able to support 8K video with 4:2:0 chroma sub-sampling (which all consumer video is) at 120fps without needing DSC compression at around 64.16 Gbps. You might even be able to support 10-bit video, which comes out at 80.2 Gbps!
As well as boosting the transmission rate over copper cables, the USB Promoter Group is developing a specification and test suite for 80Gbps active cables (which could use fiber, for example, to transmit the data). That should enable quite long cables at very high resolutions (we looked at this topic in a bit more depth here). Of course, one of the significant advantages of USB-C and USB4 is the support of power delivery (PD), so if that support is to be continued, active cables are likely to be copper/fiber hybrids with data going over the fiber and the power using the copper.
What About Thunderbolt?
One of the exciting points of the new connection is that it makes USB-C twice as fast as Thunderbolt 4. USB4 was initially based on Thunderbolt 3, but Thunderbolt 4 did not increase the speed from 40Gbps. At press time, it wasn’t clear whether Thunderbolt would also be updated to match the speed of USB-C, although it would be surprising if it didn’t, at least eventually. Intel develops Thunderbolt, although it gave over control of Thunderbolt 3 to the USB Implementers Forum (USB-IF) on a royalty-free basis to act as the base of USB4.
We reached out to the USB-IF to see if we could get more information about Version 2, but we were told that the announcement was just to put the industry on the alert for more. The full specification is expected to be released in Q4 this year, and we’ll dig in then.
(The author interviewed the USB-IF some years ago, who made it clear that the group was intent on making USB the interface of choice for everything connected to intelligent devices. It has done a pretty good job of progressing towards that aim!)
This new iteration of USB, which doubles its performance, is another example of the whole video ecosystem enabling the management of larger files and streams. Along with tools like Netflix Drive that we’ll be covering soon, it’s another sign that the extra effort to produce 8K is getting less and less significant.