[pjc50]

>> After the memory controller, bus bridges, GPUs, and DMA controller, it's probably the largest one

Probably best to distinguish between processing-heavy and throughput-heavy; apart from the GPU, all those are throughput-heavy but do very little to the data, and I think would not normally have a recognisable processor or an OS. There's the additional problem that they're required to boot, so nowhere convenient to load the OS from unless you scatter SPI flash across the board.

GPUs on the other hand have a full task-switching operating system.