A fast sort using parallelism within memory

The author models the internal structure of memory by a tree, where nodes represent memory modules (like cache, disks), and edges represent buses between them. The modules have smaller access time, capacity, and block size the nearer they are to the root. All buses may transmit blocks of data in parallel. The author gives a deterministic sorting algorithm based on greed-sort. Its running time is shown to be optimal up to a constant factor. The bound implies the number of parallel modules necessary at each hierarchy level to overcome the I/O bottlenecks of sorting. The proposed algorithm also applies to the less general models UMH (uniform memory hierarchies) and P-UMH