What kind of power draw are you getting from the D9 the wall when you set these to efficient mode? I am thinking about picking one up used and was curious about the heat and noise levels when they are run in low power mode.
In efficiency mode, power draw is about 850W and hashes about 2.1Th pool side (even though the web interface shows 2.4Th). Noise isn't reduced too much, but this isn't a very noisy unit when compared to others (e.g., bitmain S9 or A3). Temperature runs at about 60-70C.