The 16.7.1 driver for RX-480 came out. Its supposed to fix power issues with no hit on performance. AMD says up to 3 percent increase in FPS -- of course, the words "up to" allow zero as an outcome.

My 2 tests showed 0.0 and 2.5 percent FPS increase.

Reports indicate power usage down on the PCIe bus -- raised power on 6 pin connector. Net lower power. Moreover, there is a "toggle" (normally off) that lowers power draw to the "PCIe Standard". Over 5 percent FPS increase in one game -- others were less.

So, at first look, it seems like AMD did what they promised. Lower power, can set power all the way down to PCIe Standard, and increased FPS in some cases.