Table 2: Resources used for testing.

Resource Nodes Cores per node Network Chip GPU card GPUs per node

Cluster 1 8 8 InfiniBand Quad-Core AMD Opteron Processor 2352
Cluster 2 2 12 1 Gigabit Ethernet Intel Xeon E5645 GeForce GTX 580 1
Cluster 3 1 24 Intel Xeon X5650 Tesla C2075 3