The next version of USB could be one of the fastest connectors we’ve seen yet. The USB Promoter Group says that USB 4 version 2 will be capable of speeds of up to 80 Gbps, double what the original USB 4 and even Thunderbolt 4 can.
The actual technical specification from the USB Implementers Forum, which is responsible for the standard itself, has not yet been released, but the details coming out today are a bit astonishing. The Promoter Group writes in a press release that USB 4 version 2 cables will use the USB-C connector, which is to be expected, but the real bombshell is this line: “Key features of the updated USB4 solution include: Up to 80 Gbps operation, based on a new physical layer architecture, using existing 40 Gbps USB Type-C passive cables and newly defined 80 Gbps USB Type-C active cables” (emphasis of them).
Joe Balich, a spokesperson for the USB-IF, confirmed that if I went out and… buy a USB 4 cable now which was rated at 40 Gbps could reach twice those speeds in the future. Frankly, that’s extremely impressive. USB has always been good with backwards compatibility (and USB 4 version 2 is no exception), but being able to use the same cable and still take advantage of the flagship advantage of the new specification is another level.
Balich did not explain how that was technically possible, but said that “this benefit was made a requirement as the new specification was developed and details of how 80Gbps signaling is achieved will be disclosed once the final specification is released.” That will apparently be before the USB DevDays developer events scheduled for November 1 and 2 in Seattle and November 15 and 16 in Seoul.
According to the USB Promoter Group, which includes companies such as Intel, Apple, Microsoft, HP and Texas Instruments, USB-C and power specifications will be updated to “enable this higher level of data performance.” The USB 4 version 2 specification will also apparently include updates that offer better speeds when using USB 3.2 – the promoters group promises about 20 Gbps — as well as improved support for DisplayPort and PCIe as it will use the latest version of those standards (the first USB 4 will allow you to use DisplayPort 1.4a only when “tunneling”, or carrying DisplayPort and USB signals at the same time) time).
Finally, we need to talk about the name. It’s a strange move to label this as just a “version 2” of USB 4, when the jump in speed certainly feels like it justifies being called USB 5. However, the standard has been confusing for a few years now – USB 3.2 is actually a few different standards: USB 3.2 Gen 1 (aka original USB 3.0), USB 3.2 Gen 2, USB 3.2 Gen 1×2, and USB 3.2 Gen 2×2 (which is the full-fledged 20 Gbps specification). USB 4 has simplified this somewhat as it basically had the same specs and capabilities as Thunderbolt 3, but now it looks like we’re going back to a slightly more confusing naming scheme – the cable compatibility could certainly help, but I can definitely see the device spec sheets are a minefield for a while.
Not that we’ll be dealing with that anytime soon. The press release says the update is “specifically aimed at developers right now,” with final branding and marketing guides (including things like logos) coming later. Still, it’s exciting to see what’s in the pipeline and to imagine being able to transfer the data from a 4K Blu-ray in about five seconds.