So my system has an i5 2500K, not overclocked
Gtx 560 ti 448 cores edition
8gb of ddr3 1600 mhz ram
1tb 7200 rpm hdd
i currently have a 450w xfx 80+ bronze psu, but im thinking about upgrading the gpu to an msi gtx 660 twin frozr iii edition, will 450w be enough? or will i need a bigger psu?