Speedup of centrality computation with GPU as compared to CPU implementations. (a) Speedup as a function of β when network size is fixed. (b) Speedup as a function of network size n when β is fixed. (c) Speedup of four centrality metrics for a human protein-protein interaction network. (d) Speedup of four centrality metrics for a breast cancer gene co-expression network. n represents the number of nodes in the network and β controls the preferential attachment process for generating the scale-free networks. BC: betweenness centrality; CC: closeness centrality; EC: eccentricity centrality; SC: stress centrality.