Scaling Hierarchical N-Body Simulations on GPU Clusters

This paper focuses on the use of clusters of general purpose graphics processors as offload devices for tree-based N-body simulations. Whereas the behavior of these hierarchical methods has been studied in the past on CPU-based architectures, we investigate key performance issues in the context of clusters of GPUs. These include kernel organization and efficiency, the balance between tree traversal and force computation work, grain size selection through the tuning of offloaded work request sizes, and the reduction of sequential bottlenecks. The effects of various application parameters are studied and experiments are carried out to quantify gains in performance. Our studies are carried out in the context of a production-quality parallel cosmological simulator called ChaNGa. We highlight the re-engineering of the application to make it more suitable for GPU-based environments. Finally, we present scaling performance results from experiments on the NCSA's Lincoln GPU cluster.

Pritish Jetley, Lukasz Wesolowski, Filippo Gioachin, Laxmikant V. Kalé and Thomas R. Quinn, "Scaling Hierarchical N-Body Simulations on GPU Clusters", Proceedings of the ACM/IEEE Supercomputing Conference 2010. 

@inproceedings{2009ChaNGaGPU,
 author = {Jetley, Pritish and Wesolowski, Lukasz and Gioachin, Filippo and Kal{\'e}, Laxmikant V. and Quinn, Thomas R.},
 title = {Scaling Hierarchical N-body Simulations on GPU Clusters},
 booktitle = {Proceedings of the 2010 ACM/IEEE International Conference for High Performance Computing, Networking, Storage and Analysis},
 series = {SC '10},
 year = {2010},
 publisher = {IEEE Computer Society},
 address = {Washington, DC, USA},
}