To be honest, the Green500 list of the world’s greenest supercomputers can sometimes be sort of boring, because IBM is so dominant.
The company actually was behind six of the top 10 computers on the latest edition; a prototype of its next-generation Blue Gene/Q supercomputer wound up on top. It holds more than half of the top 100 positions on the list.
But there are two trends behind the latest list that are worth repeating. First, there has been a design shift. Many of the computers on the list, including the IBM Blue Gene at the top, relied on lost of lower-powered processors to help save energy. The Blue Gene model on the latest edition actually has the same number of processors as the one that made the top of the last ranking. It used slightly more power than that model (40.95 kilowatts). It has a 2097 millions of float-point operations per second (MFLOPS) per watt rating, which is the measure that the Green500 organization uses to assemble the list. That makes it the first supercomputer to exceed the 2000 MFLOPs/watt mark.
The other technology that helped several companies make this particular list: energy-efficient accelerators. The greenest “accelerator-based” supercomputer was the DEGIMA Cluster, at Nagasaki University in Japan. The computer uses AMD/ATI Radeon graphics processing units. Six of the 10 greenest supercomputers in the world use processing accelerators of some sort to complement their lower-powered central processing units.
Said Green500 founder Wu Feng:
“Over the past six months, the average efficiency of measured systems on the Green500 has increased from 230 MFLOPS/W to 256 MFLOPS/W, an improvement of 11 percent. The improvement in efficiency of accelerator-based systems on the Green500 has been even more dramatic, improving 23 percent from 573 MFLOPS/W to 707 MFLOPS/W. 70 percent of the 20 greenest supercomputers are now accelerator-based.”
I doubt many of you reading this list are a candidate for a supercomputer, but design trends have a way of making it down into mainstream data center servers. So watch these themes.
