USB 2.0 speed: 480 Mbps (mega bits per second).

512 GB (giga bytes) = 512 * 8 Gb (giga bits)

Time required to transfer 512 GB at sustained max USB 2.0 speed: 512 * 8 * 1024 / (480 * 60) minutes.

That's 145 minutes. About 2.4 hours.

That's a meaningless number. When was the last time you saw anyone even attempting to transfer hundreds of gigabytes of data using their phones? Do data hoarders now see their phones as some ideal NAS or what?

Typically twice...the last time you back up your old phone and the first time you restore to your new phone.

I've had good luck with the bottom storage level for years...until I bought a 360 GoPro...seriously huge filesizes.

I did it last week and do it regularly. My (full) 512GB iPhone takes 40+ hours to transfer over USB, I presume to to lots of small files.

You're right about the math. I misread the spec

But at the same time, I don't really yield my point. 2 hours - just plug it in at night and it's done in the morning. We routinely do things where we plug in a phone for 2 hours