Easily. I run a similar system (not this one) on an XFX XTR 550W PSU.
We need to know exactly what PSU you have. Wattage alone is not enough of a guide, nor is efficiency (Bronze, Gold...) We need to know how durable it is and how high-performance the parts are and we can only tell if we know who makes it.
EDIT
My only excuse was that the G2 had not yet been released, and I got a $20 rebate on the XTR
http://www.newegg.com/Product/Product.aspx?Item=N82E16817438053&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-PCPartPicker,%20LLC-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=
Under $70 with rebate, get it while you can,