Real-time Parallel Software Design Case Study: Implementation of the Rt-2dfft Benchmark on the Maspar Mp-x Architecture

We extended and tested the MITRE real-time embedded scalable high performance computing benchmarking concept by implementing the RT_2DFFT benchmark on the MasPar MP-X series of massively parallel processors (MPPs). The RT_2DFFT benchmark specifies a symmetric two-dimensional fast Fourier transform (FFT) within a real-time software test bench. The test bench provides the realistic stimulus for the RT_2DFFT benchmark, including input/output (I/O) from/to onboard buffers. We developed a single RT_2DFFT implementation, heavily dependent on available library functions from MasPar, that can examine both benchmark latency specifications: latency equal to the period and latency greater than the period. Through the use of the MasPar RT_2DFFT benchmark implementation, we show that the MasPar MPPs can read a two-dimensional data set or input array from an I/O buffer, perform the two-dimensional FFT, and write the processed array out to an I/O buffer—all within the one second input array inter-arrival period specified in the benchmark. If latency is permitted to extend beyond one second, we show that it may be possible to reduce the machine size by processing sufficient multiple FFTs simultaneously, so that an entire row of a two-dimensional input array is assigned to a single processor. In this instance, the RT_2DFFT benchmark runs more efficiently, because communications overhead is minimized during both I/O and FFT processing.