2008/09/14 by James Demmel, Laura Grigori, Demmel, James +5
Computer Science · #Caching and Content Delivery #Embedded Systems Design Techniques #Interconnection Networks and Systems
paper · pdf · doi:10.48550/arxiv.0809.2407
We present parallel and sequential dense QR factorization algorithms for tall and skinny matrices and general rectangular matrices that both minimize communication, and are as stable as Householder QR. The sequential and parallel algorithms for tall and skinny matrices lead to significant speedups in practice over some of the existing algorithms, including LAPACK and ScaLAPACK, for example up to 6.7x over ScaLAPACK. The parallel algorithm for general rectangular matrices is estimated to show significant speedups over ScaLAPACK, up to 22x over ScaLAPACK.