> Why waste silicon on anything but PCIe then? Power. PCIe is a fairly power hungry link. On-die parallel connections are incomparably more efficient. Special

> Why waste silicon on anything but PCIe then? Power. PCIe is a fairly power hungry link. On-die parallel connections are incomparably more efficient. Special low power links like MIPI PHYs also have their place. USB is high enough speed that you will get quite a bit of overhead from USB>PCI>memory route, and back. Audio is a particular pita, network too needs as close, and direct as possible connection to the CPU to get maximum performance.