Just had a look at the PSUs.
The Black is rated at 12v 0.7A whereas the White is 12v 1.0A
I have successfully run a 3B modem with a Black PSU for about 10 days without any noticeable change in performance.
However, I wonder if the requirement is based on future performance as greater processing power will be required for demodulating incoming 80Mbps data stream when compared with current 40Mbps and even more if BT move to a 30A profile, similarly, the additional processing power for creating the upstream at 20Mbps compared to 10Mbps. And finally, moving from a 10Mbps upstream to 20Mbps will require extra power across the wider spectrum.
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