In W10.1607 x86 when I eject a External USB HDD, it does not Power Down, I mean the Eject Procedure is not being totally finished. The Safe to Eject message appears but the light on HDD stays on and if I pull it out I can listen the Motor spinning down.
That is it not good, that will damage in short time the HDD.
The same HDD in a w10 x64 is working correctly.