The DEGIMA is a high performance computer cluster used for hierarchical N-body simulation

N-body simulation

An N-body simulation is a simulation of a dynamical system of particles, usually under the influence of physical forces, such as gravity . In cosmology, they are used to study processes of non-linear structure formation such as the process of forming galaxy filaments and galaxy halos from dark...

s at the Nagasaki Advanced Computing Center, Nagasaki University

Nagasaki University

is a national university of Japan. Its nickname is Chōdai . The main campus is located in Bunkyo-machi, Nagasaki City, Nagasaki Prefecture, Japan.- History :...

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The system consists of a 144-node cluster of PCs connected via an InfiniBand

InfiniBand

InfiniBand is a switched fabric communications link used in high-performance computing and enterprise data centers. Its features include high throughput, low latency, quality of service and failover, and it is designed to be scalable...

 interconnect. Each node is composed of 2.66 GHz Intel Core i7 920 processor, two GeForce GTX295

GeForce 200 Series

The GeForce 200 Series is the 10th generation of Nvidia's GeForce graphics processing units. The series also represents the continuation of the company's unified shader architecture introduced with the GeForce 8 Series and the GeForce 9 Series. Its primary competition came from ATI's Radeon HD 4000...

 graphics cards, 12 GB DDR3-1333 memory

DDR3 SDRAM

In computing, DDR3 SDRAM, an abbreviation for double data rate type three synchronous dynamic random access memory, is a modern kind of dynamic random access memory with a high bandwidth interface. It is one of several variants of DRAM and associated interface techniques used since the early 1970s...

 and Mellanox MHES14-XTC SDR InfiniBand host adaptor on MSI

Micro-Star International

Micro-Star International Co., Ltd is a Taiwan-based electronics company and one of the world's largest motherboard and video card manufacturers.-Overview:MSI is one of the top three motherboard and video card manufacturers worldwide...

 X58 pro-E mother board. Each graphics card has two GT200 GPU chips. As a whole, the system has 144 CPUs and 576 GPUs. It runs astrophysical N-body simulations with over 3,000,000,000 particles using the Multiple-Walk parallel treecode. The system is noted for being highly cost and energy-efficient, having a peak performance of 111 TFLOPS

FLOPS

In computing, FLOPS is a measure of a computer's performance, especially in fields of scientific calculations that make heavy use of floating-point calculations, similar to the older, simpler, instructions per second...

 with an energy efficiency of 1376 MFLOPS/watt

Performance per watt

In computing, performance per watt is a measure of the energy efficiency of a particular computer architecture or computer hardware. Literally, it measures the rate of computation that can be delivered by a computer for every watt of power consumed....

. The overall cost of the hardware was approximately US$500,000.

The name of the system is also derived from the name of a small artificial island called "Dejima

Dejima

was a small fan-shaped artificial island built in the bay of Nagasaki in 1634. This island, which was formed by digging a canal through a small peninsula, remained as the single place of direct trade and exchange between Japan and the outside world during the Edo period. Dejima was built to...

" in Nagasaki

Nagasaki

is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan. Nagasaki was founded by the Portuguese in the second half of the 16th century on the site of a small fishing village, formerly part of Nishisonogi District...

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