China's Tianhe-2 supercomputer has reclaimed the top spot for speed, almost twice as fast as the previous reigning champion, the US's Titan. Tianhe-2, unsurprisingly the follow-up to the Tianhe-1A which grabbed pole position back in 2010, is capable of 33.86 petaflops per second of processing, ranking organization TOP500 confirms, far ahead of the 17.59 petaflops per second Titan is capable of.
Tianhe-2 - which is also known as Milky Way-2 - uses 16,000 different processing nodes, each of which is equipped with a pair of Intel Xeon Ivy Bridge processors. However, they also use Xeon Phi co-processors, three to each node, which pack more than 50 cores and at least 8GB of GDDR5 memory into a PCIe expansion card.
Overall, there are 3,120,000 cores active in the supercomputer. Tianhe-2's approach, of pairing multiple CPUs, differs from that taken with the US Titan system, which harnessed the parallel processing power of GPUs with a managing tier of CPUs to organize what data they were all crunching.
However, Titan's approach has its own advantages. The supercomputer is surprisingly power-efficient - relatively speaking - thanks to the comparatively frugal K20x accelerator cores. In fact, it offers 2,143 Mflops/W, and uses less than half the power in full operation than the new first-place system.
China intends to put Tianhe-2 into operation at the National Supercomputer Center in Guangzho by the end of 2013. The machine was developed by the National University of Defense Technology, and seems to have been something of a race for the team, with the supercomputer debuting two years ahead of schedule.
There's also no small amount of pride as to how much of the system has turned out to be homegrown. "Most of the features of the system were developed in China, and they are only using Intel for the main compute part" TOP500's Jack Dongarra said of Tianhe-2. "That is, the interconnect, operating system, front-end processors and software are mainly Chinese."