Computing power is no longer the only benchmark that matters in supercomputing. Energy efficiency, as measured in performance per watt, is the key metric for the Green 500 list, which highlights the systems that combine power and efficiency. The Green 500 was established as a counterpoint to the Top500 list of the most powerful supercomputers.
Debuting at number one on the June 2013 Green 500 list is the Eurora supercomputer, with 3.208 gigaflops per watt. This result tops the energy efficiency record it set earlier this year of 3.15 gigaflops per watt. The Top500 number one Milkyway-2 (Tianhe-2) is ranked number 31 on the Green500, with 1.9 gigaflops per watt. The common feature the two systems is a heterogeneous approach, that combines two or more types of processing elements together, such as a traditional processor or central processing unit (CPU) combined with a graphical processing unit (GPU) or coprocessor.
Gigaflops per watt
“Overall, the performance of machines on the Green500 List has increased at a higher rate than their power consumption," said Wu Feng, founder of the Green500. "That's why the machines' efficiencies are going up."
The second spot on the Green500 belongs to Aurora Tigon, coming in at 3.179 gigalops per watt. Euora and Aurora Tigon are manufactured by Eurotech, and improve upon the previous greenest supercomputer in the world by nearly 30 percent. The top two spots are also powered by NVIDIA Kepler K20 GPU accelerators.
IBM BlueGene/Q systems are predominant though the 28th spot in the Green 500 list, with six in the top 10. The IBM Vulcan jumped 57 spots on the Top500 June 2013 list, and was ranked 13th on the Green 500 at 2.177 gigaflops per watt.
The top 10 most powerful supercomputers in the world, according to the June 2013 Top500 list, consume an aggregate 62.7 megawatts of power. The top 10 supercomputers combined on the Green 500 don't even reach 1 megawatt. With the DARPA’s goal of an exascale supercomputer within a power envelope of 20 megawatts, extrapolating Beacon, the previous number one supercomputer on the Green500, to exascale results in a 408 MW machine.
Seeking to raise the awareness in energy efficiency of supercomputing, the 13th edition of the Green500 list marks the Green500’s first use of new energy measurement methodologies developed in tandem with the Energy Efficient High Performance Computing Working Group, Top500, and The Green Grid.