A highly scalable Restricted Boltzmann Machine FPGA implementation

Restricted Boltzmann machines (RBMs)- the building block for newly popular deep belief networks (DBNs) - are a promising new tool for machine learning practitioners. However, future research in applications of DBNs is hampered by the considerable computation that training requires. In this paper, we describe a novel architecture and FPGA implementation that accelerates the training of general RBMs in a scalable manner, with the goal of producing a system that machine learning researchers can use to investigate ever-larger networks. Our design uses a highly efficient, fully-pipelined architecture based on 16-bit arithmetic for performing RBM training on an FPGA. We show that only 16-bit arithmetic precision is necessary, and we consequently use embedded hardware multiply-and-add (MADD) units. We present performance results to show that a speedup of 25-30X can be achieved over an optimized software implementation on a high-end CPU.