Prefetching on the Cray-T3E: a model and its evaluation
Matthias M. Mueller, Thomas M. Warschko, Walter F. Tichy · Repository KITopen (Karlsruhe Institute of Technology) · 1997
In many parallel applications, network latency causes a dramatic loss in processor utilization. This paper examines software controlled access pipelining (SCAP) as a technique for hiding network latency. An analytic model of SCAP briefly describes basic operation techniques and performance improvements. Results are quantified with benchmarks on the Cray-T3E. The benchmarks used are Jacobi-iteration, parts of the Livermore Loop kernels, and others representing six different parallel algorithm classes. These were parallelized and optimized by hand to show the performance tradeoff of severals pipelining techniques. Our results show that SCAP on the Cray-T3E improves performance compared to a blocking execution by a factor of 2.1 to 38. It also got a performance speed-up against HPF of at least 12% to a factor of 3.1 dependent on the algorithm class.