I have the TT Toughpower 700watt modular psu. it has 2x 6 pin PCIE adapters. the 4850 already takes up one so if i now get a 4870 to pair it in CF ill need to more 6pin for that. Can i use a 4 pin to 6 pin adapter or somthing? Do i need a different PSU? or should i just get another 4850? also will two 4850s out perform a single 4870?