Design space exploration for sparse matrix-matrix multiplication on FPGAs

The design and implementation of a sparse matrix-matrix multiplication architecture on FPGAs is presented. Performance of the design, in terms of computational latency, as well as the associated power-delay and energy-delay tradeoff are studied. Taking advantage of the sparsity of the input matrices, the proposed design allows user-tunable power-delay and energy-delay tradeoffs by employing different number of processing elements (PEs) in the architecture design and different block size in the blocking decomposition. Such ability allows designers to employ different on-chip computational architecture for different system power-delay and energy-delay requirements. It is in contrast to conventional dense matrix-matrix multiplication architectures that always favor the maximum number of PEs and largest block size. In our implementation, the better energy consumption and power-delay product favors less PEs and smaller block size for the 90%-sparsity matrix-matrix multiplications. While in order to achieve better energy-delay product, more PEs and larger block size are preferred.