并行FDTD和IBM BlueGene/L巨型计算机结合求解电大尺寸的电磁问题

高性能巨型计算机的快速发展正在改变着人们在计算电磁学方面的一些传统观念,特别是IBM BlueGene/L巨型计算机的出现使计算电磁学所解决的问题尺寸和时间发生了巨大的变化.IBM BlueGene/L巨型计算机可以包括多达65,536处理器和 32 TB 内存,更重要的是由于它所使用的特殊体系结构使它在4000个处理器时时域有限差分程序的并行效率仍然在百分之九十左右.测试显示,在单个CPU速度接近的情况下,一台奔腾4计算机上运行五十二天的工作量在一个包含有4000个处理器的BlueGene/L巨型计算机上仅需10min左右.虽然普通的PC机群与单个处理器相比也能快速地求解相对大的问题,但是无论是使用千兆 Ethernet、Foundry、Myrinet或者Infiniband,普通PC机群的效率都会在处理其数量超过几十个的时候快速下降.为了验证并行时有预先差分程序的正确性,我们使用并行时域有限差分程序在巨型计算机IBM BlueGene/L上模拟一个144单元的对偶极化Vivaldi阵列的抛物面天线馈源.

Solving electrically large EM problems using parallel FDTD and IBM BlueGene/L supercomputer

Rapid developments in high-performance supercomputers with up to 65,536 processors and 32 terabytes of memory have dramatically changed the landscape in computational electromagnetics. Examples are that IBM BlueGene/L supercomputers have recently made it possible to solve extremely large problems efficiently, reducing the 52 days of simulation on a single Pentium-4 processor, to only 10 minutes or so on a 4000-processor BlueGene/L system. In this article, we investigate the performance of a parallel finite difference time domain (FDTD) code on such a large BlueGene/L system. It will be shown that the efficiency of the code is excellent and can reach up to 90 percent. The code has been used in simulating a 144 dual polarized Vivaldi array for which the results will be presented to demonstrate its parallel efficiency on a BlueGene/L system.