Japanese Supercomputer Ranked 1st in Little Green500 List

Jul 8, 2010
Tetsuo Nozawa, Nikkei Electronics
The Grape-DR supercomputer system has 64 nodes, each of which consists of Intel's "Core i7-920" microprocessor, an accelerator board, Asustek Computer Inc's mother board, 18 Gbytes of DDR3 memory, x4 DDR InfiniBand, etc.
The Grape-DR supercomputer system has 64 nodes, each of which consists of Intel's "Core i7-920" microprocessor, an accelerator board, Asustek Computer Inc's mother board, 18 Gbytes of DDR3 memory, x4 DDR InfiniBand, etc.
[ If it clicks, the expanded picture will open ]
The accelerator board developed by the University of Tokyo and the National Astronomical Observatory of Japan is equipped with four "Grape-DR" accelerator chips.
The accelerator board developed by the University of Tokyo and the National Astronomical Observatory of Japan is equipped with four "Grape-DR" accelerator chips.
[ If it clicks, the expanded picture will open ]

A Japanese university and a research institute announced July 6, 2010, that their supercomputer system was ranked first in a ranking of supercomputer's performance per unit power consumption.

The supercomputer system, "Grape-DR," was ranked first in the June edition of the "Little Green500 List," which was published by the Green500.org. Its performance per unit power consumption is 815.43 MFLOPS/W, which is about 5% higher than the 773.38 MFLOPS/W of IBM Corp's system that is located in Germany and was ranked second in the list.

The Grape-DR was developed by Kei Hiraki, professor at the Department of Information Science, the University of Tokyo, and a research group led by Jyunichiro Makino, professor at the National Astronomical Observatory of Japan. For the supercomputer system, the researchers combined Intel Corp's "Core i7-920" microprocessors and the "Grape-DR" accelerator chips.

The Grape-DR accelerator chip realizes a double-precision performance of 200 GFLOPS with a power consumption of 50W. The supercomputer system is equipped with 64 pairs of a Core i7-920 microprocessor and a board mounted with four Grape-DR accelerator chips.

Without the accelerator chip, the supercomputer's performance per unit power consumption is about 150 MFLOPS/W. So, the chip enhances the performance by about five times.

To evaluate the performance, the researchers used the HPL (high performance Linpack) benchmark, which is also used for the "Top500" ranking of supercomputers. The Grape-DR accelerator chip was developed by drastically improving the versatility of the "Grape" series, which Makino's research team was developing exclusively for many-body gravity calculation in astronomy, for scientific and engineering calculations.

The Green500.org publishes the "Green500" ranking and the "Little Green500" ranking. And the Grape-DR supercomputer system is not in the former ranking. The difference between the two rankings is that the latter includes smaller-scale supercomputer systems.

While the Green500 is for the systems listed on the latest version of the Top500, the Little Green500 includes systems that were listed on the Top500 published in a year and a half ago. The computing performance of the Grape-DR supercomputer system is 23.4 TFLOPS, a little lower than 24.67 TFLOPS, which is required to be ranked 500th in the latest version of the Top500.

"(By adding more memory and boosting the interconnect speed,) it is possible to enhance the performance per unit power consumption by about 50% within this year," the university and the observatory said.