Block diagrams are very useful when trying to understand how your hardware works on the lowest levels. I recently came across a utility named hwloc that generates a block diagram of the local system. It can show you how the CPU cores and cache levels are linked and show what devices are attached to which PCIe lanes, including Audio devices, NICs, GPUs, and Storage devices. It can also do much, Much, MUCH more. Most Linux distros will have hwloc in their package repositories. After you install it just run "lstopo" in a terminal to generate a block diagram of the system and attached devices. Then read "man hwloc" and decide how far you want to go down the rabbit hole.