The Green500 List - November 2011
As in the previous edition of the list, an IBM Blue Gene/Q supercomputer tops this edition of the Green500 at 2026 MFLOPS/W. The top five positions are occupied by IBM Blue Gene/Q solutions at various locations. Seven of the top 10 greenest supercomputers in the world changed in this latest edition of the Green500 List. However, despite this significant upheaval, the ten greenest supercomputers in the world continue to follow one of two trends: (1) aggregating many low-power processors like IBM BlueGene/Q and (2) using energy-efficient accelerators, typically from the gaming/graphics market, e.g., AMD Radeon GPU, NVIDIA Tesla Fermi GPU, Cell, and Intel Knights Corner, to complement the commodity CPUs from Intel and AMD. The fastest supercomputer in the world, the K supercomputer from RIKEN in Japan, also aggregates many low-power processors. Surprisingly, while the K supercomputer increased its energy efficiency from 825 MFLOPS/W to 830 MFLOPS/W, its Green500 rank dropped from #6 in the June release to #32 now in November. That significant drop was mainly caused by the addition of new GPU-accelerated systems as well as some new high efficiency traditional CPU clusters to the latest list. Specifically, GPU-accelerated supercomputers occupy ranks #6 through #14 and #16 through 29, with high efficiency commodity machines at #15,30 and 31.
Listed below are the The Green500's Top 10 most energy-efficient supercomputers in the world as of November 2011.
| Green500 Rank | MFLOPS/W | Site* | Computer* | Total Power (kW) |
| 1 | 2026.48 | IBM - Rochester | BlueGene/Q, Power BQC 16C 1.60 GHz, Custom | 85.12 |
| 2 | 2026.48 | IBM Thomas J. Watson Research Center | BlueGene/Q, Power BQC 16C 1.60 GHz, Custom | 85.12 |
| 3 | 1996.09 | IBM - Rochester | BlueGene/Q, Power BQC 16C 1.60 GHz, Custom | 170.25 |
| 4 | 1988.56 | DOE/NNSA/LLNL | BlueGene/Q, Power BQC 16C 1.60 GHz, Custom | 340.50 |
| 5 | 1689.86 | IBM Thomas J. Watson Research Center | NNSA/SC Blue Gene/Q Prototype 1 | 38.67 |
| 6 | 1378.32 | Nagasaki University | DEGIMA Cluster, Intel i5, ATI Radeon GPU, Infiniband QDR | 47.05 |
| 7 | 1266.26 | Barcelona Supercomputing Center | Bullx B505, Xeon E5649 6C 2.53GHz, Infiniband QDR, NVIDIA 2090 | 81.50 |
| 8 | 1010.11 | TGCC / GENCI | Curie Hybrid Nodes - Bullx B505, Nvidia M2090, Xeon E5640 2.67 GHz, Infiniband QDR | 108.80 |
| 9 | 963.70 | Institute of Process Engineering, Chinese Academy of Sciences | Mole-8.5 Cluster, Xeon X5520 4C 2.27 GHz, Infiniband QDR, NVIDIA 2050 | 515.20 |
| 10 | 958.35 | GSIC Center, Tokyo Institute of Technology | HP ProLiant SL390s G7 Xeon 6C X5670, Nvidia GPU, Linux/Windows | 1243.80 |
* Performance data obtained from publicly available sources including TOP500
