Little Green500 List - June 2011
Listed below are the Little Green500's Top 10 most energy-efficient supercomputers in the world as of June 2011.
| Green500 Rank | MFLOPS/W | Site* | Computer* | Total Power (kW) |
| 1 | 2097.19 | IBM Thomas J. Watson Research Center | NNSA/SC Blue Gene/Q Prototype 2 | 40.95 |
| 2 | 1684.20 | IBM Thomas J. Watson Research Center | NNSA/SC Blue Gene/Q Prototype 1 | 38.80 |
| 3 | 1473.69 | National Astronomical Observatory of Japan | GRAPE-DR accelerator Cluster, Infiniband | 25.41 |
| 4 | 1375.88 | Nagasaki University | DEGIMA | 34.24 |
| 5 | 1031.92 | GSIC Center, Tokyo Institute of Technology | TSUBAME 2.0 Windows HPC Server Power-Efficiency Experimental | 26.00 |
| 6 | 958.35 | GSIC Center, Tokyo Institute of Technology | HP ProLiant SL390s G7 Xeon 6C X5670, Nvidia GPU, Linux/Windows | 1243.80 |
| 7 | 948.29 | GSIC,Tokyo-Institute-of-Technology | TSUBAME2.0 | 1257.00 |
| 8 | 933.06 | NCSA/UIUC | EcoG | 36.00 |
| 9 | 933.06 | NCSA | Hybrid Cluster Core i3 2.93Ghz Dual Core, NVIDIA C2050, Infiniband | 36.00 |
| 10 | 891.88 | CINECA / SCS - SuperComputing Solution | iDataPlex DX360M3, Xeon 2.4, nVidia GPU, Infiniband | 160.00 |
* Performance data obtained from publicly available sources including TOP500
