Maximum PC

Newbe to building computers, Thanks for any help you can provide! I have a 650 w power supply but want to run two Nvidia 660ti graphics cards. The power requirement is 450 W, 24 AMPS as listed on box. The build is as follows, Coolmaster case with four fans, ASUS crosshair mother board, AMD FX-8350 8 core processer, SSD, 32 gb DDR3 2400, and coolmaster CPU cooler. I still need to buy a dvd and back up hard drive. so the question is, is a 650W power supply adequated for this build? Not sure if the graphics card will get maxed running my 3d drawing programs and raytrace but definatly don't wanna damage anything either. Thank you for your help.

There's a label on power supplies that will tell you its rated output. The graphics card there to be at least 24A supplied on the 12V rail. So just to be safe, get something with 30A or higher on the 12V rail.