===firstname: David ===firstname3: Tom ===affil6: ===lastname3: Manteuffel ===email: dappelh@us.ibm.com ===keyword_other2: ===lastname6: ===affil5: ===lastname4: McCormick ===lastname7: ===affil7: ===postal: 99 Grant Ave #1 Medford, MA 02155 ===ABSTRACT: Combining nested iteration, adaptive mesh refinement, and range decomposition creates a powerful PDE solution method with reduced communication costs compared to traditional solution methods. Range decomposition partitions a PDE according to the right side of the equation, rather than the domain. If the right side is approximately equally distributed, for example from a coarse adaptive least squares solve, then range decomposition equally distributes the error and is a naturally load balanced algorithm. This algorithm is naturally suited for large distributed memory systems where intra-node communication is expensive but on node computational power is plentiful. The method will be explained, a performance model will show the scaling benefits, and numerical results for an advection-diffusion type PDE will be shown. ===affil3: University of Colorado, Boulder ===title: Nested Iteration Range Decomposition: A scalable, low communication PDE solution method with numerical results on advection-diffusion problem. ===affil2: University of Colorado, Boulder ===lastname2: Ruge ===firstname4: Steve ===keyword1: Iterative solvers/linear algebra on high concurrency node architectures ===workshop: no ===lastname: Appelhans ===firstname5: ===keyword2: NOT_SPECIFIED ===otherauths: ===affil4: University of Colorado, Boulder ===competition: no ===firstname7: ===firstname6: ===keyword_other1: ===lastname5: ===affilother: ===firstname2: John