On improving the performance of the linear solver restarted GMRES

 

Allison Baker

University of Colorado at Boulder
Applied Math Department

 

 

October 3, 200310:30 amSuite 150, Mesa Laboratory

 

 

 

 

Abstract:

 

Two approaches to improving the performance, i.e. time to solution, of an iterative linear solver algorithm are particularly viable.  First, algorithmic changes that improve convergence properties result in faster convergence due to fewer overall floating-point operations. Second, modifications to an algorithm that reduce the movement of data through memory greatly impact performance because of the growing gap between CPU performance and memory access time.  Ideally, a balance is achieved between improving the efficiency of an iterative linear solver from a memory-usage standpoint and maintaining favorable numerical properties. We discuss the restarted generalized minimum residual (GMRES) method in the context of both approaches to improving performance.