Vector performance prediction of kernel loops on Earth Simulator

Yokokawa, Mitsuo; Saito, Minoru*; Hagiwara, Takashi*; Isobe, Yoko*; Jinguji, Satoshi*

Earth simulator is a distributed memory parallel system which consists of 640 processor nodes connected by a full crossbar network. Each processor node is a shared memory system which is composed of eight vector processors. The total peak performance and main memory capacity are 40Tflops and 10TB, respectively. A performance prediction system GS for the Earth Simulator has been developed to estimate sustained performance of programs. To validate accuracy of vector performance prediction by the GS, the processing times for three groups of kernel loops estimated by the GS are compared with the ones measured on SX-4. It is found that the absolute relative errors of the processing time are 0.89%,1.42% and 6.81% in average for three groups. The sustained performance of three groups on a processor of the Earth Simulator have been estimated by the GS and those performance are 5.94Gflops,3.76Gflops and 2.17Gflops in average.