Complete very slow
As you know, the new iPhone 15 Pro and 15 Pro Max received a USB-C port with support for the USB 3.0 standard. However, the included cable only supports USB 2.0, and so far the only Apple-branded cable with normal speed is the Thunderbolt 4 cable for $70. Phone Arena decided to compare the latter with the included cable, the $15 USB 3 cable from Amazon, and the cable that comes with an external SSD.
iPhone 15 Pro Bundled Cable vs. $70 Thunderbolt Cable and $15 USB 3 Cable.
In this case, a Samsung SSD was used for tests, but this does not matter.
So, the first test was to copy a two-minute 4K ProRes video from the phone to the SSD, which weighs 9.86 GB. With the included iPhone cable, the process took 4 minutes and 5 seconds, but in all other cases it took only 27 seconds.
The second test was to copy a file from an iPhone to a MacBook Pro. The included cable from the iPhone showed a result of 4 minutes and 38 seconds, with the cable from Amazon the process took 1 minute and 9 seconds, and the transfer via the Thunderbolt cable took 1 minute and 6 seconds.
Thus, for such tasks, it is not worth buying a $70 cable, since a regular USB 3.0 cable is enough. However, in Apple-branded stores, customers are dissuaded from purchasing third-party cables.