Reevaluating Amdahl's Law in the Multicore Era
Microprocessor architecture has entered the multicore era. Recently, the researchers presented a pessimistic view of multicore scalability. Their analysis was based on Amdahl's law (i.e. fixed-workload condition) and challenged readers to develop better models. In this paper, the authors analyze multicore scalability under fixed-time and memory-bound conditions and from the data access (memory wall) perspective. They use the same hardware cost model of multicore chips used by the researchers, but achieve very different and more optimistic performance models. These models show that there is no inherent, immovable upper bound on the scalability of multicore architectures.