Interesting that Apple chose a SiP rather then a SoC. The major disadvantage of a SiP is its size, since its a bunch of subsystems manufactured independantly. The CPU may be in 28nm, Memory in 14nm, Peripherals in 180nm. They are assembled inside the package by various techniques - vertical stacking, horizontal stacking. The other disadvantage is that the manufacturing costs are much higher.

I guess the main reason for this by Apple was because a SiP you can connect a GaAs RF chip to a Silicon memory or microprocessor chip.

Our time will come, we are here with the answer.

"targeting the 40nm technology node widely used for highly integrated systems-on-chip (SoC)." - Sept 2 Poet NR

SoC Advantages:

• Lower overall system costs, resulting from reduced component and printed circuit board costs
• Increased performance, because of shorter signal paths between processor, memory and other logic components
• Lower power consumption – Fewer components, reduced power consumption and extended battery life.

• Smaller physical size, because fewer components results in a smaller board size.

Seems like a no brainer :)