huvik :
no that is enough power, but what brand is your psu?
This is wrong. A system with an R9 380 will be fine with a quality 500-550w unit.
http://www.realhardtechx.com/index_archivos/Page362.htm
A quality 750w unit like the EVGA G2 is sufficient for 2 x 380s in Crossfire.
So no, probably not the power supply. At least not from the power supply being insufficient to power the card. It could be defective.