How much PSU wattage would I need for my build?

impreza0109

Honorable
Oct 22, 2013
9
0
10,520
Hello. I'm new to the forum and I've read so many stuff about computers in general here. I'd like to ask how mcuh wattag I would need from a PSU for my build?

Intel Core i5 3570 non-k
Cooler Master Hyper 212 Evo
Asrock Z77 Pro3
Gskill Ripjaws X 8GB RAM
Inno3D GTX 760 iChiLL HerculeZ 3000
a cheapo DVD-RW

I was getting inclined to get a 500 watt PSU as my friend suggested, he has almost the same exact components and it has been sufficient for him. The guy at my local PC store said I need 700 watts, I asked him why? I'm not going to SLI, and i'm not going to OC. He can't give me a clear explanation, he just insisted on it. Can you guys help me out? Thanks. :)