The Green Index: A Metric for Evaluating System-Wide Energy Efficiency in HPC Systems

Abstract

In recent years, the high-performance computing (HPC) community has recognized the need to design energy-efficient HPC systems. The main focus, however, has been on improving the energy efficiency of computation, resulting in an oversight on the energy efficiencies of other aspects of the system such as memory or disks. Furthermore, the energy consumption of the non-computational parts of a HPC system continues to consume an increasing percentage of the overall energy consumption. Therefore, to capture a more accurate picture of the energy efficiency of a HPC system, we seek to create a benchmark suite and associated methodology to stress different components of a HPC system, such as the processor, memory, and disk. Doing so, however, results in a potpourri of benchmark numbers that make it difficult to "rank" the energy efficiency of HPC systems. This leads to the following question: What metric, if any, can capture the energy efficiency of a HPC system with a single number?To address the above, we propose The Green Index (TGI), a metric to capture the system-wide energy efficiency of a HPC system as a single number. Then, in turn, we present (1) a methodology to compute TGI, (2) an evaluation of system-wide energy efficiency using TGI, and (3) a preliminary comparison of TGI to the traditional performance-to-power metric, i.e., floating-point operations per second (FLOPS) per watt.

Supercomputers Keeping People Warm in the Winter

“…While the top500 ranking of the fastest supercomputers has existed since 1993, the green500 ranking of the most efficient supercomputers has only existed since 2007 [3,5]. This statistic alone heralds the shifting of current priorities.…”

“…The diagonal in the graph is the practical boundary of power and scale limitations [7]. It is notable that the November 2013 edition of the Green500 list was the first where the average power used by the supercomputers on the list decreased compared to the previous edition [5].…”

“…Finally, district heating may not be available, depending on the location of the center. [5]. The global trend pushes growth vertically.…”

Assessing Power Monitoring Approaches for Energy and Power Analysis of Computers

“…. ) but they are circumscribed to either one [9] or a few benchmarks types [10]. Furthermore, the most prevailing infrastructure comprises only an external wattmeter [1,11].…”

Robust motion estimation on a low-power multi-core DSP

“…Furthermore, processor manufacturers are now concerned for concepts such as green computing. The aim is to develop more efficient chips not only in terms of performance rates (throughput measured in terms of floating-point operations per second (FLOPS) or Mbits per second) but also energy efficiency [15]. Besides modern and efficient multi-core CPUs, hardware accelerators such as GPUs or Intel MIC (Intel Corp., Santa Clara, CA, USA), or reconfigurable devices (FPGAs), one of the latest additions on specificpurpose architectures applied to general-purpose computing are low-power digital signal processors (DSPs).…”