Sorting in Parallel External-Memory Multicores

In this paper, we introduce a model for multicore architectures, which takes into explicit consideration the cache-oriented nature of inputs and outputs in modern CPUs. In addition, we study the fundamental problem of sorting comparable items using this model. We provide algorithms that are efficient in terms of the number of parallel I/O’s. We also provide lower bounds that show that our algorithms are within a constant factor of optimal, for reasonable values of parameters characterizing the number of processors, the size of each processors memory, the size of cache blocks, and the number of items to be sorted.