For almost 18 days my Asus has been running on the upgraded 126.96.36.199 firmware with a memory stick (256M) and it only consumed a total of 3.73 kWh. This results in server which only needs about 8.6 Watt. Amazing when you compare it to the old Pentium Tower I used as SVN sever, which I now realize was only a Watt to hot noise converter.
Has any body done some measurements on a mechanical disk? Does it power down when idle?
The consumption is (almost) too small to get a good reading.