The Inquirer reports the Green 500 list illustrates that AMD's FirePro S10000 GPGPU card beats NVIDIA's Tesla K20X in terms of energy efficiency. Interestingly, newcomer Xeon Phi 5110P seems to have even better MFLOPS/W than AMD's card. You can check out the full list over here, but bear in mind that it looks at the power consumption of the entire supercomputer, and not just of the HPC accelerators.
AMD's Firepro S10000 accelerator card is based on the firm's current generation Graphics Core Next architecture and boasts peak performance of 5.91 TeraFLOPS in single-precision floating point and 1.48 TeraFLOPS in the all important double-precision floating point category. The firm's latest GPGPU card stacks up well against Nvidia's Tesla K20 series accelerator cards on paper, and going by the Green 500, it can match and surpass the efficiency of clusters boasting Nvidia's latest kit.
While the Top 500 list remains the most prestigious league in high performance computing, in recent years the Green 500 list has been gaining popularity because it takes into account power utilisation, a vital factor when deciding what kit to deploy in the real world.