wait........i think you cant run DUAL 939.............it should be DUAL 940...

http://www.newegg.com/app/ViewProdu...property&DEPA=0

cheapest dual 940
http://www.newegg.com/app/ViewProdu...-151-125&depa=0
230 USD

expensive one
http://www.newegg.com/app/ViewProdu...-151-135&depa=0
554 USD