Improving Energy-Efficiency of Capsule Networks on Modern GPUs

Convolutional neural networks (CNNs) have become the compelling solution in machine learning applications as they surpass human-level accuracy in a certain set of tasks. Despite the success of CNNs, they classify images based on the identification of specific features, ignoring the spatial relationships between different features due to the pooling layer. The capsule network (CapsNet) architecture proposed by Google Brain's team is an attempt to address this drawback by grouping several neurons into a single capsule and learning the spatial correlations between different input features. Thus, the CapsNet identifies not only the presence of a feature but also its relationship with other features. However, the success of the CapsNet comes at the cost of underutilization of resources when it is run on a modern GPU equipped with tensor cores (TCs). Due to the structure of capsules in the CapsNet, quite often, functional units in a TC are underutilized which prolong the execution of capsule layers and increase energy consumption. In this work, we propose an architecture to eliminate ineffectual operations and improve energy-efficiency of GPUs. Experimental measurements over a set of state-of-the-art datasets show that the proposed approach improves energy-efficiency by 15% while maintaining the accuracy of CapsNets.