According to
preliminary specifications presented in July 2017, USB 3.2 should enable a speed of up to 20 Gbit/s (2.5 GB/s). For comparison: bFor USB 3.1 (Gen1) it was 4.8 Gbit/s (maximum real 3.2 Gbit/s), for USB 3.1 (Gen2) it was 10 Gbit/s, or 7.2 Gbit/s in real terms.
Synopsis has now published a first speed test: a normal USB-C cable from Belkn was used together with a USB 3.2 device under Linux and a USB 3.2 host under Windows 10 with standard USB drivers. The transmission takes place via two of the four 10 Gbit/s lanes via multi-lane operation - together, theoretically, 20 Gbit/s bandwidth is available. The Synopsis test achieves a speed of 1.6 GB/s - the theoretical bandwidth of 2.5 GB/s is reduced by the overhead of the communication - as expected. The speed was maintained for the entire test period of 60 minutes.

USB 3.2 Benchmark
But even after the future upgrade, which does not require any new cables but - with backward compatibility - an upgrade of the client and host controllers, USB 3.2 still lags far behind the speed of 40 Gbit/s Thunderbolt 3. The first hardware that supports USB 3.2 will probably not be available until late 2018 to early 2019 - only the USB-C connector is supported.more about USB vs Thunderbolt 3 via USB-C in our
basic article.