cross-posted from: https://discuss.tchncs.de/post/22828099
USB was supposed to rule them all but it’s now a mess of standards sharing the same connector. Different speeds, voltage, charging protocols, alt modes, even the number of pins used is variable… For those asking, the thing is available on Kickstarter
Yes because being able to handle 5 amps does not mean it having the USB 3+ lines, but only V+, D+, D-, and a CC line. A cable that supports 5 amps has a build in chip (eMarker) that is powered by the other CC pin (which is not led through the cable) that is in that case called Vconn. For fast data, you have two additional pairs of data wires with better isolation from interference (like in HDMI, DP, Ethernet etc.) How well those insulation work is rated with the 5, 10, 20, 40, 80 gb/s spec. Theoretically, a good 10gb/s cable may be able to handle more bandwidth. Additionally for thunderbolt, you as well need a chip in the cable for some stuff I have not learned yet.
From what I know, the chip in the cable is for active cables to get lengths of 2 meters plus, but comes at the cost of USB speeds when used for non-Thunderbolt applications. Shorter passive cables generally can hit 40gbps for TB and 20 gbps for USB.