• May 2011
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Chinese Chip Wins Energy-Efficiency Crown.

IEEE Spectrum (05/11) Joseph Calamia

The next Chinese supercomputer will use the Godson-3B processor, which can perform 128 billion floating-point operations per second while consuming only 40 watts, which tops the performance per watt of competing systems by at least 100 percent. The processor relies on a modified mesh network that features additional direct core connections to move data efficiently. The eight-core chip consists of two four-core clusters where each core sits on a corner of a square of interconnects. Each corner also is linked to its opposite through two diagonal interconnects that form an X through the square’s center. Both four-core units are connected via a crossbar interconnect, and the chip’s developers expect the scalability of their modified mesh to be an advantage as designers place more cores on future chips. Boosting the number of cores in a mesh puts a strain on the system, but Tilera’s Matthew Mattina says a mesh interconnect offers bandwidth scaling superior to that of the ring configuration typical of most microprocessors. Godson architect Yunji Chen says a mesh design also supports more favorable latency.


Panel: Wall Ahead in Multicore Programming.

EE Times (05/03/11) Rick Merritt

A panel of experts at the recent Multicore Expo said that programmers will need new tools and methods to reap the benefits of increasingly parallel chips. “The wall is there,” says Nokia Siemens Networks’ Alex Bachmutsky. “We probably won’t have any more products without multicore processors [but] we see a lot of problems in parallel programming.” Rewriting existing programs is expensive, and although some algorithms can be changed, Bachmutsky notes that changing all the cell towers and phones is not doable. An audience member also warned that developers can no longer expect next-generation processors to boost the performance of their apps. LSI engineer Rob Munoz said that parallel software is difficult to develop, maintain, and evolve. And managing multithreaded applications where threads may move between different cores also is a problem, points out consultant Mike Anderson. He says the industry needs to understand what it means to be parallel before even thinking about a new programming language.


Graphene Optical Modulators Could Lead to Ultrafast Communications.

UC Berkeley News Center (05/08/11) Sarah Yang

University of California, Berkeley researchers have developed graphene-based technology that could revolutionize digital communications. The researchers, led by Berkeley professors Xiang Zhang and Feng Wang, built a tiny optical device using graphene that can switch light on and off, a fundamental aspect of a network modulator. The researchers say that graphene-based modulators could enable consumers to stream full-length high-definition movies onto a smartphone in just a few seconds. “This new technology will significantly enhance our capabilities in ultrafast optical communication and computing,” Zhang says. The researchers achieved a modulation speed of one gigahertz, but theorized that speeds as high as 500 gigahertz on a single modulator are possible. Graphene can absorb a broad spectrum of light, which allows the material to carry more data than conventional modulators, which only operate at a bandwidth of up to 10 nanometers. “What we see here and going forward with graphene-based modulators are tremendous improvements, not only in consumer electronics, but in any field that is now limited by data transmission speeds, including bioinformatics and weather forecasting,” Zhang says.