A parallel SSOR preconditioner for lattice QCD

✍ Scribed by S. Fischer; A. Frommer; U. Glässner; Th. Lippert; G. Ritzenhöfer; K. Schilling

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 919 KB
• Volume: 98
• Category: Article
• ISSN: 0010-4655
• DOI: 10.1016/0010-4655(96)00089-6

✦ Synopsis

We present a parallelizable SSOR preconditioning scheme for Krylov subspace iterative solvers which proves to be efficient in lattice QCD applications involving Wilson fermions. Our preconditioner is based on a locally lexicographic ordering of the lattice points. In actual Hybrid Monte Carlo applications with the bi-conjugate gradient stabilized method BiCGstab, we achieve a gain factor of about 2 in the number of iterations compared to conventional odd-even preconditioning. Whether this translates into similar reductions in run time will depend on the parallel computer in use. We discuss implementation issues using the 'Eisenstat-trick' and machine specific advantages of the method for the APE100/Quadrics parallel computer. In a full QCD simulation on a 512-processor Quadrics QH4 we find a gain in cpu-time of a factor of 1.7 over odd-even preconditioning for a 243 x 40 lattice.