
Snoop-Based Multiprocessor
Design
The large differences we see in the performance, cost, and scale of symmetric multi-
processors on the market rest not so much on the choice of the cache coherence
protocol but rather on the design and implementation of the organizational struc-
ture that supports the logical operation of the protocol. Protocol trade-offs are well
understood, and most machines use a variant of the protocols described in the last
chapter. However, the latency and bandwidth that is achieved with a protocol
depend on the bus design, the cache design, and the integration with memory, as
does the engineering cost of the system. Thi ...