[laxis96]

Talking about low power, I am currently running a headless HP laptop which I recovered from a friend. This thing sports an i3-5005U CPU (2GHz 2c/4t) and idles at 4W measured at the wall!

Well, it's not powerful by definition but it can easily handle file sharing and torrenting (for my library of Linux ISOs obviously) while staying powered on 24/7. The fan also turns off at idle so it's totally silent.

What's funny is that this machine is currently resting on top of my decommissioned home server (Xeon E5-2697v2, 64GB RDIMMs, Supermicro X9) which idled around 100W...