Parallel neural network training on Multi-Spert

Multi-Spert is a scalable parallel system built from multiple Spert-II nodes which we have constructed to speed error backpropagation neural network training for speech recognition research. We present the Multi-Spert hardware and software architecture, and describe our implementation of two alternative parallelization strategies for the backprop algorithm. We have developed detailed analytic models of the two strategies which allow us to predict performance over a range of network and machine parameters. The models' predictions are validated by measurements for a prototype five node Multi-Spert system. This prototype achieves a neural network training performance of over 530 million connection updates per second (MCUPS) while training a realistic speech application neural network. The model predicts that performance will scale to over 800 MCUPS for eight nodes