On 9/4/19 8:20 AM, Patrick O'Callaghan wrote:
For a USB drive it probably doesn't make much difference. Output
will
be buffered and speed is limited by the USB interface.
If you aren't specifying a block size, the default block size tends to
involve more round-trips through the kernel and through the USB bus. In
that case, it isn't the USB interface bandwidth that causes slow
transfers, but the latency involved in each tiny request.
I'd test this, but I seem to have left my bag of USB drives at home
today. :)
Feel free to 'dd' a drive to /dev/null with and without a specified
large block size to demonstrate the difference. Maybe I'm wrong.