i am currently running 2 Antminer S1's off of a Corsair 1050HX great power supply and it still leaves room to over clock and not run the power supply at 100% which kills them quickly

I have a friend that has 2 corsair 1050 hx's with 5 Antminer S1's plugged into them and they run fine on high clock speeds - 2.5 S1's on each power supply