The Sun Fireplane SMP interconnect in the Sun Fire 3800-6800

Worldwide server revenue is dominated by symmetric multiprocessor (SMP) systems. The architecture and implementation of the interconnect that maintains system-wide cache coherency is critical to the performance and scalability of SMP systems. This paper describes the Sun/sup TM/ Fireplane SMP interconnect protocol, and the implementation choices we made for the mid-sized Sun Fire/sup TM/ 3800-6800 servers.