does an APU use any power if nothing connected to it

[RobTi]

Hi i have an AMD A4 5300 CPU for my whs 2011 and it will be running headless so will it use any power if there is no display connected to it

Robert

[HalloweenJack]

if its turned on then yes it uses power

[Hicks12]

yes it will still use power, the actual power usage will be reduced though due to less load on the gpu part however if you're running gpu intensive tasks without a monitor it still will use a similar amount.
I assume you are using it as a server which would mean the power usage is specifically from the cpu so powerusage will certainly be less but how much is impossible to tell without your own tests .

[scaryjim]

Hmmm, as far as I can tell the APU graphics don't have ZeroCore so sadly you won't get any of the long idle benefits the 7-series discrete cards have. However, the card will drop into an idle state when it's not being used which will heavily reduce the power draw. The A-series APUs are all pretty efficient at idle power draw, and your WHS will be running at idle for the vast majority of the time.