It looks like the CPU and GPU are really close, which makes sense because it looks like there's a ton of pins shared between the two. Ultimately designing a ci

It looks like the CPU and GPU are really close, which makes sense because it looks like there's a ton of pins shared between the two. Ultimately designing a circuit board layout is an optimization problem. You usually have some constraints, like how close chips can be before they start interfering with each other magnetically, where the I/O will be, and where you need holes to mount the board. Then you either try to be a pathing optimizer yourself or you run a program that will layout your board for you. I'm not sure about the XBox, but game consoles sometimes have faster Memory->GPU pipelines than normal PCs to speed up render times, which might be why the GPU is the most central component.