By way of example, the group says that a USB 3.2 host connected to a USB 3.2 storage device will be capable of 2GB/s transfer over a "superspeed" certified USB 3.1 cable. "When we introduced USB Type-C to the market, we intended to assure that USB Type-C cables and connectors certified for SuperSpeed USB or SuperSpeed USB 10 Gbps would, as produced, support higher performance USB as newer generations of USB 3.0 were developed," said USB 3.0 Promoter Group Chairman Brad Saunders.
You should take those Thunderbolt-like numbers with a grain of salt, however. USB 3.0 or 3.1 devices (which confusingly use USB-C cables) rarely come close to their certified speeds. For instance, The Wirecutter found that the fastest USB 3.0 flash drive, the Extreme CZ80, could read and write at 254 MB/s and 170 MB/s, tops -- half of what USB 3.0 is capable of. (Some USB 3.1 superspeed SSD drives can saturate a USB 3.0 connection, however.)
Still, flash storage is advancing rapidly, thanks to 64-layer and higher tech from Toshiba, Intel, Samsung and WD, and those kind of speeds are handy if you're editing RAW or 4K video. The USB 3.0 Promoter Group (with Apple, HP, Intel, Microsoft and others as members) says that the 3.2 spec will be finalized by the end of 2017, so don't expect to see any devices until then. In the meantime, we'll hear more about it in September this year in North America during the USB Developer Days.