They probably did, yeah. Is that guy passively cooled? If so, they couldn't afford too many watts before the chip would start into thermal runaway and burn up.

BM1384 was also the S5, S5+ chip. 5.5GH I believe is 100MHz clocked, but with adequate power and cooling the chip could do 400MHz/22GH. Because of the non-linear relationship between speed and power (a higher speed requires a higher voltage because more energy is needed to flip the switches faster, but a higher voltage will also push a higher current into the switches' capacitive gate loads and resistive transition loads, so the effect multiplies), quadrupling the speed to the max would cause a more than quadruple increase in power, from under 2 watts to above 10 watts at the chip.