TBH I haven't tested it yet since the GTX 1070 card is still in shipping state, but I guess ihattendorf has provided detailed information :) If I can complete the setup before HN locks me from editing, I will edit this post
Okay so I manage to complete the build, on idle this is about 80w, but notice I have a 1070 card, which costs around 37w according to nvidia-smi, so if you don't need a graphics card, I'd say 40w - 50w is more than enough in idle.