Instrumentation for Accurate Energy-to-Solution Measurements of a Texas Instruments TMS320C6678 Digital Signal Processor and Its DDR3 Memory

Architectural choices for High-Performance Computing systems have once again become interesting with energy efficiency for targeted workloads now being a major decision factor. A detailed understanding of the energy consumption of major system components during code execution is critical for evolving architectures towards enhanced energy efficiency. The focus of this paper is on the measurement system hard-and software we designed and implemented for the assessment of the energy-to-solution of HPC workloads for the Texas Instruments TMS320C6678 (6678) Digital Signal Processor. The 6678´s thermal design power falls between x86 server processors and mobile CPUs and so does its floating-point and memory system capabilities. Yet, compared to those types of processors in corresponding CMOS technology, it offers a potentially significant energy advantage. The measurement system is described together with a thorough error analysis. Measurements are processed out-of-band minimizing the impact on the measured system. Sample observations of the energy efficiency of the 6678 and its memory system are included for illustration.