The November 2013 release of the Green500 list has been announced at the SC13 conference in Denver, Colorado.
Continuing the trend from previous years, heterogeneous supercomputing systems dominate the top 10 spots of the Green500. Heterogeneous systems use computational building blocks that consist of two or more types of 'computing brains'.
These types of computing brains include traditional processors (CPUs), graphics processing units (GPUs), and co-processors. In this edition of the Green500, one system smashes through the four-billion floating-point operation per second (gigaflops) per watt barrier.
TSUBAME-KFC, a heterogeneous supercomputing system developed at the Tokyo Institute of Technology (TITech) in Japan, tops the list with an efficiency of 4.5 gigaflops/watt. Each computational node within TSUBAME-KFC consists of two Intel Ivy Bridge processors and four Nvidia Kepler GPUs. All systems in the top ten of the Green500 use a similar architecture – Intel CPUs combined with Nvidia GPUs.
Wilkes, a supercomputer housed at Cambridge University, takes the second spot. The third position is filled by the HA-PACS TCA system at the University of Tsukuba. Of particular note, this list also sees two petaflop systems, each capable of computing over one quadrillion operations per second, achieve an efficiency of over three gigaflops/watt, namely Piz Daint at Swiss National Supercomputing Center and TSUBAME 2.5 at Tokyo Institute of Technology. Thus, Piz Daint is the greenest petaflop supercomputer on the Green500. As a point of reference, Tianhe-2, the fastest supercomputer in the world according to the Top500 list, achieves an efficiency of 1.9 gigaflops/watt.
Compilers of the list say it marks a number of 'firsts'. It is the first time that a supercomputer has broken through the four gigaflops/watt barrier. Second, it is first time that all of the top 10 systems on the Green500 are heterogeneous systems. Third, it is the first time that the average of the measured power consumed by the systems on the Green500 dropped with respect to the previous edition of the list.