On Intel’s side, the motherboard layout is particularly straightforward, with a CPU connector and The main connectors the North and South bridge then its sub-connections the, memory modules and the graphics cards in the Northbridge while the Southbridge controls the other PCI slots and the USB and storage needs. While AMD has the same concept, they still have The North and South Bridge, but fro moat of AMD board chipset the North and South bridge are integrated together, that’s why most AMD boards never have a North bridge chip near the CPU and the graphics But a large heat sink in the bottom of the board.
As you say it is outrageous how can two types of chipsets can be in the same die, well it is simple, they just got a bigger die compound to place the chip on and there you go, a large chip that hold up the North and South Bridge together, with this type of design from the integration of the North and South Bridge is to counter the usage of another Chip die to cut the cost of manufacture and increase the performance of the chip (for the purpose of having a faster bus transfer of information from the chipset form the both bridges). While what is the use of it, just to increase transfer rate of the board, no biggy! Well it is a biggy for AMD however with Intel still get the performance crown of this year, AMD try all too hard to get every single score just to beat some Intel based chips.
With another reason is that Intel needs a separate North and South Bridge is that the memory still needs to be passed on the North Bridge, while AMD in the other hand doesn’t need to pass the North Bridge but just pass to the CPU via Hyper threading the memory. So the use of the Northbridge to transfer info in the memory is a thing of the past. While for those with a heat sink in between the CPU with AMD it is just the integrated graphics that AMD have placed to cool down the graphics when used in a high degree (well, overclocked to what I mean) or they just used the old way on separating the North and South bridge when the North is integrated with the Video card in.
With this layout from AMD is the benefit of having the memory controller integrated in the CPU can sometimes increase the Bus speeds in latency and memory bandwidth that’s why AMDs platform is more competitive with Intel with memory speeds, that’s one they have beaten Intel, but for me just buy a lower timing count and a big memory in and Intel platform and there you go, but for the desperate, a cheap way to have a faster memory speed or a AMD diehard fan why not buy one good for boot times and loading of games in a reasonable price.
