[...] Do u guys think Corsair Ax1500i could do 6-7 1080 tis at a time or should I stick with 5 , need to get eight pin to dual 8 pin cables .
I wouldn't put more than four 1080ti on an AX1500i. Depends on a Ti and how far you push it, but in my case it was switching off randomly with five EVGA SC Blacks running at 100-120% power during summer.