为解决并行应用程序使用FFTW(Fastest Fourier Transform in the West)并行软件包所面临的计算规模难以扩展、数据结构变动大、实现不同数据结构间通信难度大、接口不确定等问题,在JASMIN框架内设计实现FFT并行解法器.该解法器封装了数...为解决并行应用程序使用FFTW(Fastest Fourier Transform in the West)并行软件包所面临的计算规模难以扩展、数据结构变动大、实现不同数据结构间通信难度大、接口不确定等问题,在JASMIN框架内设计实现FFT并行解法器.该解法器封装了数据分布存储、数据通信等并行计算细节,通过重新分布存储数据,调用一维FFT变换实现高维FFT的并行计算,并提供规范接口,支撑用户简便地实现FFT的并行计算.数值测试表明,该解法器具有很好的并行性能.该解法器已应用于激光等离子体成丝不稳定性的数值模拟并行程序,它在2048个处理器上的并行效率可达80%以上.展开更多
CFD is a ubiquitous technique central to much of computational simulation such as that required by aircraft design.Solving of the Poisson equation occurs frequently in CFD and there are a number of possible approaches...CFD is a ubiquitous technique central to much of computational simulation such as that required by aircraft design.Solving of the Poisson equation occurs frequently in CFD and there are a number of possible approaches one may leverage.The dynamical core of the MONC atmospheric model is one example of CFD which requires the solving of the Poisson equation to determine pressure terms.Traditionally this aspect of the model has been very time consuming and so it is important to consider how we might reduce the runtime cost.In this paper we survey the different approaches implemented in MONC to perform the pressure solve.Designed to take advantage of large scale,modern,HPC machines,we are concerned with the computation and communication behaviour of the available techniques and in this text we focus on direct FFT and indirect iterative methods.In addition to describing the implementation of these techniques we illustrate on up to 32768 processor cores of a Cray XC30 both the performance and scalability of our approaches.Raw runtime is not the only measure so we also make some comments around the stability and accuracy of solution.The result of this work are a number of techniques,optimised for large scale HPC systems,and an understanding of which is most appropriate in different situations.展开更多
文摘为解决并行应用程序使用FFTW(Fastest Fourier Transform in the West)并行软件包所面临的计算规模难以扩展、数据结构变动大、实现不同数据结构间通信难度大、接口不确定等问题,在JASMIN框架内设计实现FFT并行解法器.该解法器封装了数据分布存储、数据通信等并行计算细节,通过重新分布存储数据,调用一维FFT变换实现高维FFT的并行计算,并提供规范接口,支撑用户简便地实现FFT的并行计算.数值测试表明,该解法器具有很好的并行性能.该解法器已应用于激光等离子体成丝不稳定性的数值模拟并行程序,它在2048个处理器上的并行效率可达80%以上.
文摘CFD is a ubiquitous technique central to much of computational simulation such as that required by aircraft design.Solving of the Poisson equation occurs frequently in CFD and there are a number of possible approaches one may leverage.The dynamical core of the MONC atmospheric model is one example of CFD which requires the solving of the Poisson equation to determine pressure terms.Traditionally this aspect of the model has been very time consuming and so it is important to consider how we might reduce the runtime cost.In this paper we survey the different approaches implemented in MONC to perform the pressure solve.Designed to take advantage of large scale,modern,HPC machines,we are concerned with the computation and communication behaviour of the available techniques and in this text we focus on direct FFT and indirect iterative methods.In addition to describing the implementation of these techniques we illustrate on up to 32768 processor cores of a Cray XC30 both the performance and scalability of our approaches.Raw runtime is not the only measure so we also make some comments around the stability and accuracy of solution.The result of this work are a number of techniques,optimised for large scale HPC systems,and an understanding of which is most appropriate in different situations.
