Adams, Mark F.Brown, JedKnepley, Matthew G.Samtaney, Ravi2017-02-232017-02-232016Adams, Mark F., Brown, Jed, Knepley, Matthew G., et al.. "Segmental refinement: A multigrid technique for data locality." <i>SIAM Journal on Scientific Computing,</i> 8, no. 4 (2016) Society for Industrial and Applied Mathematics: C426-C440. http://dx.doi.org/10.1137/140975127.https://hdl.handle.net/1911/93975We investigate a domain decomposed multigrid technique, termed segmental refinement, for solving general nonlinear elliptic boundary value problems. We extend the method first proposed in 1994 by analytically and experimentally investigating its complexity. We confirm that communication of traditional parallel multigrid is eliminated on fine grids, with modest amounts of extra work and storage, while maintaining the asymptotic exactness of full multigrid. We observe an accuracy dependence on the segmental refinement subdomain size, which was not considered in the original analysis. We present a communication complexity analysis that quantifies the communication costs ameliorated by segmental refinement and report performance results with up to 64K cores on a Cray XC30.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1137/140975127