We tested the peak power consumption of a NAS at the wall during a run of CrystalDiskMark 7 as this version of the benchmark runs the read and write benchmark suites separately so it's easier to monitor what power the device is using during each function.
Asustor quote power consumption figures for the Drivestor 4 of 22.8W in use and 9.41W (Disk Hibernation) using WD Red 3TB drives (4.8 W active read/write, 3.1W idle and 0.4W standby and sleep). Using 6TB Red drives (WD60EFRX) we saw an average of 31.7W for active read/writes and 9W idle. The WD60EFRX is a slightly more power-hungry drive at 5.3W active and 3.4W idling.