WINE1: SpecialPurpose Computer forNBody Simulations with a Periodic Boundary Condition
Abstract
We have developed WINE1 (Wave space INtegrator for Ewald method), a specialpurpose computer for Nbody simulations with a periodic boundary condition. In Nbody simulations with a periodic boundary condition such as cosmological Nbody simulations, we use the Ewald method to calculate the gravitational interaction. With the Ewald method, we can calculate the interaction more accurately than a calculation with other methods, such as the PM method, the P(3) M method, or the tree algorithm. In the Ewald method, the total force exerted on a particle is divided into contributions from real space and wavenumber space so that the infinite sum can converge exponentially in both spaces. WINE is a specialpurpose computer used to calculate the interaction in wavenumber space. WINE is connected to a host computer via the VME bus. We have developed the first machine, WINE1. It is made of one board having a size of 38 cm by 40 cm, on which 31 LSI chips and 46 IC chips are wirewrapped. The peak speed of WINE1 is equivalent to 480 Mflops. The summation in real space is calculated using a GRAPE system, another specialpurpose computer for the direct calculation of the interparticle force. For example, we can perform a cosmological Nbody simulation for N=80,000 (500 steps) within a week if we use GRAPE2A for the summation in real space and WINE1 for that in wavenumber space.
 Publication:

Publications of the Astronomical Society of Japan
 Pub Date:
 June 1993
 Bibcode:
 1993PASJ...45..361F
 Keywords:

 COSMOLOGY;
 GALAXIES: EVOLUTION;
 GALAXIES: FORMATION;
 NUMERICAL METHODS;
 SPECIAL PURPOSE COMPUTER