Green500
The Green500 is a biannual ranking of supercomputers, from the TOP500 list of supercomputers, in terms of energy efficiency.  The list measures performance per watt using the TOP500 measure of high performance LINPACK benchmarks at double-precision floating-point format.

History
, an Appro International, Inc. Xtreme-X supercomputer (Beacon) topped the Green500 list with 2499 LINPACK MFLOPS/W.  Beacon is deployed by NICS of the University of Tennessee and is a GreenBlade GB824M, Xeon E5-2670 based, eight cores (8C), 2.6 GHz, Infiniband FDR, Intel Xeon Phi 5110P computer.

, the Eurotech supercomputer Eurora at Cineca topped the Green500 list with 3208 LINPACK MFLOPS/W.  The Cineca Eurora supercomputer is equipped with two Intel Xeon E5-2687W CPUs and two PCI-e connected NVIDIA Tesla K20 accelerators per node. Water cooling and electronics design allows for very high densities to be reached with a peak performance of 350 TFLOPS per rack.

, the L-CSC supercomputer of the Helmholtz Association at the GSI in Darmstadt Germany topped the Green500 list with 5271 MFLOPS/W and was the first cluster to surpass an efficiency of 5 GFLOPS/W. It runs on Intel Xeon E5-2690 Processors with the Intel Ivy Bridge Architecture and AMD FirePro S9150 GPU Accelerators. It uses in rack watercooling and Cooling Towers to reduce the energy required for cooling.

, the Shoubu supercomputer of RIKEN outside Tokyo Japan topped the Green500 list with 7032 MFLOPS/W. The then-top three supercomputers of the list used PEZY-SC accelerators (GPU-like that use OpenCL) by PEZY Computing with 1024 cores each and 6–7 GFLOPS/W efficiency.

, DGX SaturnV Volta, using "NVIDIA DGX-1 Volta36, Xeon E5-2698v4 20C 2.2GHz, Infiniband EDR, NVIDIA Tesla V100", tops Green500 list with 15,113 MFLOPS/W, while ranked only 469th on Top500. It's only a little bit more efficient than the much bigger Summit ranked 2nd while 1st on Top500 with 14,719 MFLOPS/W, using IBM POWER9 CPUs while also with Nvidia Tesla V100 GPUs.

, Japanese Preferred Networks' supercomputer, using their own chips (and Intel's), "MN-Core Server, Xeon 8260M 24C 2.4GHz, MN-Core, RoCEv2/MN-Core DirectConnect" tops the Green500 list with 21,108 MFLOPS/W, while ranked only 393rd on Top500. Of the big systems making top 10 of the Top500 list, Selene supercomputer is second on the Green500 list (7th on Top500), using Nvidia GPUs and AMD CPUs close behind in efficiency while much larger with 20,518 MFLOPS/W, and HPC5 supercomputer 6th on both lists, also using Nvidia GPUs but IBM's Power CPUs, and similarly Summit the previous top supercomputer, now in second place (8th on green500), and the current top supercomputer Fugaku (9th on Green500) uses British-design ARM-based CPUs with instruction set extensions developed by Japanese Fuijitu, the maker of the supercomputer, while notably GPUs are absent at 14.665 MFLOPS/W.

Green 500 List

Historical development 
energy efficiency of top-ranked computers (Gigaflops/Watt)

References

Supercomputer benchmarks