RockPro64 power consumption

[TOMillr]

OTOH I have nothing in my PCIe (yet) and only a BT dongle in USB. Measuring my power consumption at the wall (with a Brennenstuhl meter) 7.25W max when idle, often a lot less

My results, measured at the mains line, with a no-name switched-mode 12V/3A PSU,  a 64 GB eMMC module installed, and a HDMI HD TV + a USB keyboard + a USB mouse plugged in:

• screen off past 10 min timeout: 3.1 W
  

What's the explanation for the discrepancy between the two idle values?

I'm looking to build a power-efficient NAS on basis of a RockPro64. But since the NAS would sit idle for most of the time, power consumption during Idle state is of the main concern for me.