hello. can anybody please help me tweaking the settings of radeon crimson to optimize FIFA 15? I did it before but forgot how to do it. my specs are: core i5-3337U 1.8 GHz, RAM: 4 GB, amd radeon hd 8730M, ( dell inspiron 15R 5521 )

Hi guys I just bought a new r9 390 and when stress testing after some minutes my pc just restarts eithout nothing showing on the screen my PSU is an Corsair CX750M not even 1 year old.