  Improvements in the performance of deep neural networks have often come
through the design of larger and more complex networks. As a result, fast
memory is a significant limiting factor in our ability to improve network
performance. One approach to overcoming this limit is the design of sparse
neural networks, which can be both very large and efficiently trained. In this
paper we experiment training on sparse neural network topologies. We test
pruning-based topologies, which are derived from an initially dense network
whose connections are pruned, as well as RadiX-Nets, a class of network
topologies with proven connectivity and sparsity properties. Results show that
sparse networks obtain accuracies comparable to dense networks, but extreme
levels of sparsity cause instability in training, which merits further study.
