according to http://pcengines.ch/apu2b4.htm it is possible to add a 2.5" hard drive powered by the 5V 2pin connector on the board. As there are two MiniPCIe card slots, which can supply 2 SATA ports each via a relatively cheap adaptor (about 20 euros), the whole unit could in theory support up to 5 x 2.5" HDDs and also 1 x mSATA SSD.
As the controllers do not support staggered spinup, one has to calculate the worst amount of power drawn at startup, which would be for about 1A for most 5400rpm hard drives and 1.1A for 7200rpm. SSD would take about 0.6A, so this would sum up to about 6A @ 5V. The base board uses about 1.5A @ 12V according to the manual, but 2A is suggested.
So, can I simply take an external power supply which is rated for 5A@12V / 60W and everything works fine, or is the internal power circuit of the board limited in a certain way and/or I will be killing the board this way?
Thanks in advance!