It's certainly in package rather than on the same chip. The process required to make DDR is different from what you use to make the core's logic. The DRAM chi

It's certainly in package rather than on the same chip. The process required to make DDR is different from what you use to make the core's logic. The DRAM chips might be literally stack on top of the CPU chip, though. Apple does things that way in the iPhone IIRC.