Heya,

Same conclusion I came to when I saw the first announcement of GMO;s 7nm Miners. Whoever designed this board, really did a piss poor job in regulating power consumption.

But, in all honesty it could be coming down to the limitation of the first generation of 7nm chips just not being up to spec. (Yes 7nm is still in first generation stages, these could also be just out of proof of concept stage)

Bitmain will most likely make a better machine since they wont be using Samsung, and will be sticking with TSMC who generally makes much better semiconductor technology. You wont see better systems until  last quarter of 2018 to first quarter of 2019 as most 7nm fabs are only being completed around this time right now.