Performance Evaluation Of The QUADRICSMachine In Solving Chemical Rate Equations Of AState-of-the-art Photochemical Module

Abstract

The integration of stiff, very coupled, ordinary differential equations which describe pollutant chemical reactions is the most intensive computational task of photochemical models, since it requires at least 70% of the total CPU time. As a consequence of the local nature of these equations, the integration can be performed very efficiently by a SIMD architecture. In this work we present the porting of QSSA (Quasi Steady State Approximation) chemical solver of CALGRID photochemical model on the SIMD massively parallel platform Quadrics/APElOO which offers, in QH4 configuration, a peak performance of 25 Gflops.