The influence of two modern compiler infrastructures on the energy consumption of the HPCG benchmark

As energy consumption plays a more and more critical role in high-performance computing installations, investigating the influence of the different system components and their share w.r.t. energy consumption is of great interest. The compiler is one of the key parts of the software environment. Unlike processor frequency and power limits, the influence of the compiler and its sets of optimizations on energy consumption has not received much attention in the field of high-performance computing yet. In this paper, we present a study which compares the GNU and Intel compiler infrastructures with each other concerning the energy consumption of the generated code. We use the HPCG benchmark as target application and perform energy measurements using both single-socket and whole-machine measurements. Our results show that the compiler can have a strong influence on energy consumption: For one configuration, the binary compiled with the Intel compiler consumes approximately twice the amount of energy of the binary compiled with the GNU compiler, even though the runtime is practically the same.