(Georgia Institute of Technology, 2006-08-30)
Madduri, Kamesh; Bader, David A.; Berry, Jonathan W.; Crobak, Joseph R.
We present an experimental study of parallel algorithms for solving the single source
shortest path problem with non-negative edge weights (NSSP) on large-scale graphs.
We implement Meyer and Sander's Δ-stepping algorithm and report performance results on the Cray MTA-2, a multithreaded parallel architecture. The MTA-2 is a
high-end shared memory system offering two unique features that aid the efficient implementation of irregular parallel graph algorithms: the ability to exploit fine-grained
parallelism, and low-overhead synchronization primitives. Our implementation exhibits
remarkable parallel speedup when compared with a competitive sequential algorithm,
for low-diameter sparse graphs. For instance, Δ-stepping on a directed scale-free graph
of 100 million vertices and 1 billion edges takes less than ten seconds on 40 processors
of the MTA-2, with a relative speedup of close to 30. To our knowledge, these are the
first performance results of a parallel NSSP problem on realistic graph instances in the
order of billions of vertices and edges.