Also, there are very few PC power supplies that come with even close to enough PCIe plugs as the S7 needs 10. They were never made to be ran with PC power supplies.
the evga 1300 g2 can't really run an s-7 at full speed.
if the op has the ability to lower the speed on his s-7 to about 4000 hash rate
he could do 2 cables per board
this setup would pull 4000 x .26 = 1040 watts
1040/6 = 173 watts a cable
@ op the advice above is pretty much how to run your s-7 on a 1300 evga
you would have a quieter machine if you do it. and it would hash at 4000 vs 4800