There's always a cost to running with more cores. We expect the Threadripper platform to pull the most juice from the socket, yet it could be argued that the numbers are actually pretty decent for the amount of power on tap.
Perhaps the power consumption is low because our chosen benchmark, HandBrake, is not able to tax all cores sufficiently. We then ran a 10-minute Blender test and found that consumption rose to 258W. All in all, you don't need a silly-powerful PSU to run Threadripper, especially at stock speeds.