Patrick H. Worley

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The design of the Parallel Ocean Program (POP) is described with an emphasis on portability. Performance of POP is presented on a wide variety of computational architectures, including vector architectures and commodity clusters. Analysis of POP performance across machines is used to characterize performance and identify improvements while maintaining(More)
Fairness is an important issue when benchmarking parallel computers using application codes. The best parallel algorithm on one platform may not be the best on another. While it is not feasible to reevaluate parallel algorithms and reimplement large codes whenever new machines become available, it is possible to embed algorithmic options into codes that(More)
BlueGene/P (BG/P) is the second generation BlueGene architecture from IBM, succeeding BlueGene/L (BG/L). BG/P is a system-on-a-chip (SoC) design that uses four PowerPC 450 cores operating at 850 MHz with a double precision, dual pipe floating point unit per core. These chips are connected with multiple interconnection networks including a 3-D torus, a(More)
The last decade has witnessed a rapid proliferation of superscalar cache-based microprocessors to build high-end computing (HEC) platforms, primarily because of their generality, scalability, and cost effectiveness. However, the growing gap between sustained and peak performance for full-scale scientific applications on conventional supercomputers has(More)
The scientific simulation capabilities of next generation high-end computing technology will depend on striking a balance among memory, processor, I/O, and local and global network performance across the breadth of the scientific simulation space. The Cray XT4 combines commodity AMD dual core Opteron processor technology with the second generation of Cray's(More)
The spectral transform method is a standard numerical technique for solving partial diierential equations on a sphere and is widely used in atmospheric circulation models. Recent research has identiied several promising algorithms for implementing this method on massively parallel computers; however, no detailed comparison of the diierent algorithms has(More)
We describe the design of a parallel global atmospheric circulation model, PCCM2. This parallel model is functionally equivalent to the National Center for Atmospheric Research's Community Climate Model, CCM2, but is struc-tured to exploit distributed memory multicomputers. PCCM2 incorporates parallel spectral transform, semi-Lagrangian transport, and load(More)
Oak Ridge National Laboratory installed a 32 processor Cray X1 in March, 2003, and will have a 256 processor system installed by October, 2003. In this paper we describe our initial evaluation of the X1 architecture, focusing on microbenchmarks, kernels, and application codes that highlight the performance characteristics of the X1 architecture and indicate(More)
The Community Atmosphere Model (CAM) version 5 includes a spectral element dynamical core option from NCAR’s High-Order Method Modeling Environment. It is a continuous Galerkin spectral finite element method designed for fully unstructured quadrilateral meshes. The current configurations in CAM are based on the cubedsphere grid. The main motivation for(More)