im running my q9450 at 3.7 right now with an XFX BE core 216 OC'd (which calls for 40A according to XFX...NOT 38A as according to newegg specs...putting my psu 1A above recommended
) with a 550vx...and i have zero problems. its all about the quality.
OP i'd go with the corsair 750tx....it has plenty enough amps and will leave you a bit of headroom as well. the 650tx will cover your needs, but the 750tx is like 10 bucks more and has 8 more amps on its rail (60 vs 52).
"nagasama no longer drinks tecate, or streaks out of the night for anything, and he has a fine wife so he has no use for your girlfriend...she is safe..."