Earlier quoted context omitted.
> Actual maximum data throughput is very hard to know. The only way to really "know" how much data can flow through a cable is with an expensive oscilloscope or cable tester. Couldn't you just do a data transfer test over the cable and check the error rate? At least in theory, the controller might not report enough I guess.
If you are just wanting "to use it", sure. If you are building a cable for a specific purpose, or want to actually ensure that it will work, use test equipment. IT interconnect closet vs. air vehicle.
Isn't that what most people here are really wanting? I don't imagine most people here are seriously wanting to know the exact extreme measurements, just "can this cable reasonably do what I need from it? Does it do what it claims on the label generally?"