(1) If you wrote "Doc" because you meant to post in SRB's channel, the issue is that you're running the wrong miner if you care about power draw and efficiency.

(2) A general note that applies to all miners: the transitions from CNv1 to CNv8 to CN/r have added more and more computations to the main loop. CNv8 added a square root and a division, CN/r went further and replaced it with a string of random operations with a lot of multiplications that chew up cycles on gpus, but this work is still only related to two read/write mem accesses as in the original CN algorithm. The Heavy/Saber main loop adds a third mem access and a single division. The main loop is > 90% of the runtime, and the differences between the CN/r and Haven main loops are enough to push the power consumption significantly. The important factor is the amount of computational work necessary per mem access.