Unfortunately "USB 3.2" is just a version of the standard, which does not give any information about the performance of a USB port or device.
USB 5 Gb/s = USB 3.2 gen 1, available on Type A or Type C connectors (or on devices on a special extended micro B connector)
USB 10 Gb/s = USB 3.2 gen 2, available on Type A or Type C connectors
USB 20 Gb/s = USB 3.2 gen 2x2, available only on Type C connectors
Moreover, "5 Gb/s" is a marketing lie. The so-called USB of 5 Gb/s has a speed of 4 Gb/s (the same as PCIe 2.0). On the other hand, 10 Gb/s and 20 Gb/s, have the claimed speeds, so USB of 10 Gb/s is 2.5 times faster than USB of 5 Gb/s, not 2 times faster.
10 Gb/s USB and Ethernet have truly the same speed, but the USB overhead is somewhat higher, leading to a somewhat lower speed. However, the speed shown in TFA, not much higher than 7 Gb/s seems too low, and it may be caused by the Windows drivers. It is possible that on other operating systems, e.g. Linux, one can get a higher transfer speed.
The fact that you had to list all of the versions and speeds at the top of your post is illustrative of what the parent was trying to say. We can all look up what speed is associated with what version, but it’s not exactly a consumer friendly experience.
A few computer manufacturers do the right thing and they mark the speed on the USB ports, removing ambiguities, for example ASUS does this on my NUCs and motherboards.
Unfortunately, there are too many who do not do this, even among the biggest computer vendors.
> mark the speed on the USB ports, removing ambiguities
Unfortunately it's not true.
Quiz: what happens when a device capable of 20Gbps is plugged into a port marked as 40Gbps?
I can't tell if this is a trick question that has something to do with a quirk of USB running multiple lanes in parallel to get higher speeds.
Because if not then it's the same as any specification for connecting devices that allows for multiple speeds. It runs at the lowest of the max speeds supported of everything in the chain.
That's exactly the issue. I'm just pointing out that it's a fantasy to hope for simple numbering of max supported speeds will simplify the current USB mess.
It will not.
Consumers would expect plugging a 20Gbps device into a 40Gbps port should result in 20Gbps negotiated speed. In reality it will mostly likely end up at 10Gbps (or less) because of the mess.
Older Thunderbolt devices were not compatible with USB, so plugging them into an USB Type C port would not work.
Newer Thunderbolt/USB 4 devices do not have any technical reason for preventing them to work as USB 3.2 2x2, i.e. to work at 20 Gb/s when plugged into a 20 Gb/s host port, and vice-versa for 20 Gb/s devices plugged into a USB 4/Thunderbolt host port, because both Thunderbolt and 20 Gb/s USB need the same wires in the cable and connector.
I do not know if all USB 4 controllers also work at 20 Gb/s (USB 3.2 2x2), but if they do not work that should be considered a bug.
Thats just port speed, charging and other features are all a crapshoot on USB making Thunderbolt the sane version of the "USB-C" family where it requires a set of things (speed, charging wattage)
> Moreover, "5 Gb/s" is a marketing lie.
It's not a lie, the b just stands for baud not bit ;-)
That is technically correct, but "b" has never been an accepted abbreviation for baud (which was Bd) and the naming of the first versions of the PCIe, USB 3 and SATA speeds, which were done by Intel, were obviously in contradiction with the industry standards and intended to confuse the customers.
Previously to these standards promoted by Intel, the 1 Gb/s Ethernet used the same encoding and it was rightly called by everybody "1 Gb/s", not "1.25 Gb/s", because the gross bit rate has absolutely no importance for the users of a communication standard.
Only Intel invented this marketing trick, calling PCIe 1.0 and 2.0 as 2.5 and 5 Gb/s, instead of 2 and 4 Gb/s, and similarly for USB and SATA, where e.g. SATA 3 is called 6 Gb/s, but its speed is 4.8 Gb/s.