Before revision:  Here we present a multi-level approach to identifying the performance gap between HPC and cloud computing and to isolate several variables that contribute to this gap by dividing our experiments into (i) hardware and system microbenchmarks and (ii) user applications.
After revision:  Here we present a multi-level approach to identifying the performance gap between HPC and cloud computing , isolating different variables that contribute to this gap by dividing our experiments into (i) hardware and system microbenchmarks and (ii) user applications.