video card crashing

Hello all,

Let me present my rig first of all. It is a custom build ( my first one ever (probably the last one as well) )
PSU = Corsair 750 Watt modular
Motherboard = Asus F2A55
APU = AMD a8 5600k Quad core 3.6Ghz
Coolermaster Hyper TX3 EVO Heatsink & fan
Samsung 4GB DDR3 1600Mhz x2
WD 1TB Sata 3
Nvidia Geforce GTX650 1GB

So my problem is that my PC crashes every time I watch a video or a movie . I cannot do anything at all, the only solution is reset button. When I enter in my BIOS and set my rig in performance setting, It will crash quite often and its either my PSU or video card screaming like hell. The only solution for this is when I set my rig into power saving mode from BIOS. Now.....if I do that , I cant really play Fifa15 not even in low quality.

Can anybody help with some suggestions pls ?