Accession Number : ADA321329
Title : Performing Out-of-Core FFTS on Parallel Disk Systems.
Descriptive Note : Contract rept.,
Corporate Author : INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
Personal Author(s) : Cormen, Thomas H. ; Nicol, David M.
PDF Url : ADA321329
Report Date : DEC 1996
Pagination or Media Count : 16
Abstract : The Fast Fourier Transform (FFT) plays a key role in many areas of computational science and engineering. Although most one dimensional FFT problems can be solved entirely in main memory, some important classes of applications require out-of-core techniques. For these, use of parallel input output systems can improve performance considerably. This paper shows how to perform one-dimensional FFTs using a parallel disk system with independent disk accesses. We present both analytical and experimental results for performing out-of-core FFTs in two ways: using traditional virtual memory with demand paging, and using a provably asymptotically optimal algorithm for the Parallel Disk Model (PDM) of Vitter and Shriver. When run on a DEC 2100 server with a large memory and eight parallel disks, the optimal algorithm for the PDM runs up to 144.7 times faster than in-core methods under demand paging. Moreover, even including I/O costs, the normalized times for the optimal PDM algorithm are competitive, or better than, those for in-core methods even when they run entirely in memory.
Descriptors : *PARALLEL PROCESSORS, *FAST FOURIER TRANSFORMS, *DISKS, ALGORITHMS, INPUT, OPTIMIZATION, COMPUTATIONS, MODELS, COSTS, MEMORY DEVICES, INTERNAL, INPUT OUTPUT DEVICES, MAGNETIC CORES.
Subject Categories : Numerical Mathematics
Distribution Statement : APPROVED FOR PUBLIC RELEASE