How the world’s most powerful supercomputer inched toward the exascale – ieee spectrum

Photo: Jack Dongarra An Efficient Engine: Sunway TaihuLight’s computations-per-watt improvement is even more impressive than its raw computing power.

In June, the ranks of the Top500 list were rearranged, and the title of world’s most powerful supercomputer was handed off to a new machine—China’s Sunway TaihuLight.

The Wuxi-based machine can perform the Linpack Benchmark—a long-standing arbiter of supercomputer prowess—at a rate of 93 petaflops, or 93 quadrillion floating-point operations per second. Npower electricity power cut This performance is more than twice that of the previous record holder, China’s Tianhe-2. Year 6 electricity What’s more, TaihuLight achieves this capacity while consuming 2.4 megawatts less power than Tianhe-2.

Such efficiency gains are important if supercomputer designers hope to reach exascale operation, somewhere in the realm of 1,000 Pflops. Gas oil mix ratio chart Computers with that capability could be a boon for advanced manufacturing and national security, among many other applications. K gas station jobs China, Europe, Japan, and the United States are all pushing toward the exascale range. Gas upper stomach Some countries are reportedly setting their sights on doing so by 2020; the United States is targeting the early 2020s. Electricity voltage in paris But two questions loom over those efforts: How capable will those computers be? And can we make them energy efficient enough to be economical?

We can get to the exascale now “if you’re willing to pay the power bill,” says Peter Kogge, a professor at the University of Notre Dame. Cheapest gas in texas Scaling up a supercomputer with today’s technology to create one that is 10 times as big would demand at least 10 times as much power, Kogge explains. Gas utility bill And the difference between 20 MW and 200 MW, he says, “is the difference [between having] a substation or a nuclear power plant next to you.”

Kogge, who led a 2008 study on reaching the exascale, is updating power projections to cover the three categories of supercomputers built today: those with “heavyweight” high-performance CPUs; those that use “lightweight” microprocessors that are slower but cooler, and so can be packed more densely; and those that take advantage of graphics processing units to accelerate computation. Electricity usage “They produced a processor that can deliver high arithmetic performance but is very weak in terms of data movement” —Jack Dongarra, University of Tennessee

TaihuLight follows the lightweight approach, and it has made some sacrifices in pursuit of energy efficiency. Electricity transmission loss Based on its hardware specs, TaihuLight can, in theory, crunch numbers at a rate of 125 Pflops. Gas 2015 The machine reaches 74 percent of this peak theoretical capacity when running Linpack. 3 gases that cause global warming But it does not fare as well on a new alternative benchmark, High Performance Conjugate Gradients (HPCG), which is designed to reflect how well a computer can perform more memory- and communications-intensive, real-world applications. Electricity 1800s When it runs HPCG, TaihuLight utilizes just 0.3 percent of its theoretical peak abilities, which means that only 3 out of every 1,000 possible floating-point operations are actually used by the computer. Gas bubble in back By comparison, Tianhe-2 and the United States’ Titan, the second- and third-fastest supercomputers in the Top500 rankings, respectively, can take advantage of just over 1 percent of their computing capacity. Electricity human body Japan’s K computer, currently ranked fifth on the list, achieved 4.9 percent with the HPCG metric.

“Everything is a balancing act,” says Jack Dongarra, a professor at the University of Tennessee, Knoxville, and one of the organizers of the Top500. Gas up asheville “They produced a processor that can deliver high arithmetic performance but is very weak in terms of data movement.” But he notes that the TaihuLight team has developed applications that take advantage of the architecture; he says that three projects that were finalists for this year’s ACM Gordon Bell Prize, a prestigious supercomputing award, were designed to run on the machine.

TaihuLight uses DDR3, an older, slower memory, to save on power. A gaseous mixture contains Its architecture also uses small amounts of local memory near each core instead of a more traditional memory hierarchy, explains John Goodacre, a professor of computer architectures at the University of Manchester, in England. Gas vs diesel cars He says that while today’s applications can execute between 1 and 10 floating-point operations for every byte of main memory accessed, that ratio needs to be far higher for applications to run efficiently on TaihuLight. M gasbuddy The design cuts down on a big expense in a supercomputer’s power budget: the amount of energy consumed shuttling data back and forth.

“I think what they’ve done is build a machine that changes some of the design rules that people have assumed are part of the requirements” for moving toward the exascale, Goodacre says. Electricity voltage in china Further progress will depend, as the TaihuLight team has shown, on end-to-end design, he says. Q gas station cleveland ohio That includes looking not only at changes to hardware—a number of experts point to 3D stacking of logic and memory—but also to the fundamental programming paradigms we use to take advantage of the machines.