Date Added: Oct 2010
Clouds enable novel execution modes often supported by advanced capabilities such as autonomic schedulers. These capabilities are predicated upon an accurate estimation and calculation of runtimes on a given infrastructure. Using a well-understood high-performance computing workload, the authors find strong fluctuations from the mean performance on EC2 and Eucalyptus-based cloud systems. The analysis eliminates variations in IO and computational times as possible causes; they find that variations in communication times account for the bulk of the experiment-to-experiment fluctuations of the performance.