%0 Journal Article
%T A Bulk-Parallel Priority Queue in External Memory with STXXL
%A Timo Bingmann
%A Thomas Keh
%A Peter Sanders
%J Computer Science
%D 2015
%I arXiv
%X We propose the design and an implementation of a bulk-parallel external memory priority queue to take advantage of both shared-memory parallelism and high external memory transfer speeds to parallel disks. To achieve higher performance by decoupling item insertions and extractions, we offer two parallelization interfaces: one using "bulk" sequences, the other by defining "limit" items. In the design, we discuss how to parallelize insertions using multiple heaps, and how to calculate a dynamic prediction sequence to prefetch blocks and apply parallel multiway merge for extraction. Our experimental results show that in the selected benchmarks the priority queue reaches 75% of the full parallel I/O bandwidth of rotational disks and and 65% of SSDs, or the speed of sorting in external memory when bounded by computation.
%U http://arxiv.org/abs/1504.00545v1