Based on their previous lines, the even units have always been underclocked. Maybe you'll see an S6 with a 16-17 chip string instead of a 14 chip string, lowering the voltage to get better efficiency.
S5 had 15 chip per board.( 7+8)+(7+8)=30
Sorry, 30. But the chain is 15*.
Same principle applies though. More chips for lower voltages and better efficiency.
*Voltage chain, that is. The chip chain is 30 per board.