i want to use a risers with 6pin cable but with molex or sata it's  less power than the pcie needs(75)w and i don't want to use the  main pcie entrances on the power supply becuse i want tp use them for the cards so i was thinking is there a cable i can use  to convert this output to 8pin ?  even if i use 2 to get one 8pin ? can i use that?