As you can likely infer from the earlier discussion on power consumption and TBPs, in order to reach these higher clockspeeds AMD and their partners had to increase their GPU voltages. Relative to both our RX 480 and RX 470, the differences are quite significant. Overall voltages have increased by around 0.1v when using AMD’s reference clocks, and closer to 0.15v for the full factory overclocks. As a result the highest frequencies on these two cards are very expensive in terms of power, and it explains a great deal about why AMD needed to increase TBPs by 30-35W just to add another 40-80MHz to the boost clock.