Bus topology was chosen because it is the least expensive and most reliable under the standard.
The
bus topology suggests AMD's Ryzen-derived APUs will continue to benefit from higher-clocked memory.
Vodrazka, "Application of Passive Optical Network with Optimized
Bus Topology for Local Backbone Data Network", Microwave and Optical Technology Letters, vol.
A star network generally requires more cable than a
bus topology, but a failure in a star network will only take down one computer's network access, and not the entire network.
For transmission lines, keep the spacing between adjacent signal paths at least twice the line width for microstrip or stripline to keep the absolute worst-case, near-end noise in a
bus topology less than 5%.