Researchers have searched for scalable alternatives to the symmetric multiprocessor (SMP) architecture since it was first introduced in 1982. This paper introduces an alternative view of the relationship between scalable technologies and SMPs. Instead of replacing large SMPs with scalable technology, we propose new scalable techniques that allow large SMPs to be tied together efficiently, while maintaining the compatibility with, and performance characteristics of, an SMP. The trade-offs of such an architecture differ from those of traditional, scalable, Non-Uniform Memory Architecture (cc-NUMA) approaches. WildFire is a distributed shared-memory (DSM) prototype implementation based on large SMPs. It relies on two techniques for creating application-transparent locality: Coherent Memory Replication (CMR), which is a variation of Simple COMA/Reactive NUMA, and Hierarchical Affinity Scheduling (HAS). These two optimizations create extra node locality, which blurs the node boundaries to ...