Before revision:  Results are presented demonstrating high per-node performance and near-ideal parallel scalability with rates of more than four quadrillion elementwise comparisons achieved per second  on the ORNL Titan system  .
After revision:  Results are presented demonstrating high per-node performance and near-ideal parallel scalability with rates of more than four quadrillion elementwise comparisons achieved per second with the latest optimized code on the ORNL Titan system .