If you keep everything running stock and don't crank everything up I don't see any problem as long as the 650w sees a good amount of amps on the 12v rails. You don't want to have the supply pulled from simply not providing enough.
What make and model is that? The specifications will show what that offers.
Correction, the specifications seen when looking back at your original post show 18 amps for the most part. http://www.newegg.com/Product/Produc...82E16817815001
You'll want to run them stock until you get into a heftier supply like the one seen at the link.