The bus that connects the CPU to main memory on the motherboard. I/O buses, which connect the CPU with the systems other components, branch off of the system bus.
The system bus is also called the frontside bus, memory bus, local bus, or host bus.
System bus speeds and G3 graphics cards Describes the dual bus architecture of the G3 card and how it affects the performance of Macs. The article describes why faster system-bus speeds might reduce performance and stability for some systems.