On Sat, 20 Jun 2020 22:20:35 +0100
Chris Green  wrote:

> All I'm saying is that the USB standard doesn't provide even 2 amps.

 The standards for USB 3.1 over a USB-C connector specifies up to
three amps at five volts. Supplies that support the USB power delivery
standard (which requires USB-C connectors) can provide up to five amps at
twenty volts - yes that's right a hundred watts (there are some supplies
that exceed the spec and provide more than five amps).

 My work laptop with the screaming fast processor, 4K screen and
NVMe storage runs on USB power delivery!

> Thus a 'USB' cable that conforms to the USB specification doesn't need
> to be able to carry that much current.

 USB 2.0 stops at half an amp sure, but that's not what powers a
PI-4.

> If a Pi requires more than the USB specification allows then its power
> supply *and* cable are "more than USB".

 Nope is uses USB-3.1 over USB-C connectors - with a spec of up to
three amps.

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