CPU: I-7 3770 3.4mhz
CPU Cooling Fan: Stock
Motherboard: Asus P8H61-M Pro
RAM: Kingston 8GB DDR3 (2x4GB)
Graphics Card: AMD Sapphire Radeon R9 380 NITRO 4gb ddr5
Power Supply: Powercooler 600w RS-600-PCAR-E3
Hard Drive: Western Digital CAVIAR GREEN 1TB SATA 7200RPM 64MB WDC WD10EARS-00MVWB0
That power supply that you have does not supply the R9 380 with enough power and I am VERY certain that is your problem, I would suggest that you buy a 750 Watt PSU just to have some more headroom.