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Pentium Pro insideAs an entry for the 1997 Gordon Bell performance prize, we present results from two methods of solving the gravitational N-body problem on the Intel Teraflops system at Sandia National Laboratory (ASCI Red). The first method, an O(N2) algorithm, obtained 635 Gigaflops for a 1 million particle problem on 6800 Pentium Pro processors. The second solution method, a tree-code which scales as O(N log N), sustained 170 Gigaflops over a continuous 9.4 hour period on 4096 processors, integrating the motion of 322 million mutually interacting particles in a cosmology simulation, while saving over 100 Gigabytes of raw data. Additionally, the tree-code sustained 430 Gigaflops on 6800 processors for the first 5 time-steps of that simulation. This tree-code solution is approximately 105 times more efficient than the O(N2) algorithm for this problem. As an entry for the 1997 Gordon Bell price/performance prize, we present two calculations from the disciplines of astrophysics and fluid dynamics. The simulations were performed on two 16 Pentium Pro processor Beowulf-class computers (Loki and Hyglac) constructed entirely from commodity personal computer technology, at a cost of roughly $50k each in September, 1996. The price of an equivalent system in August 1997 is less than $30. At Los Alamos, Loki performed a gravitational tree-code N-body simulation of galaxy formation using 9.75 million particles, which sustained an average of 879 Mflops over a ten day period, and produced roughly 10 Gbytes of raw data.
Document ID
19990047350
Acquisition Source
Headquarters
Document Type
Other
Authors
Warren, M. S.
(Los Alamos National Lab. NM United States)
Becker, D. J.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Sterling, T.
(California Inst. of Tech. Pasadena, CA United States)
Salmon, J. K.
(Los Alamos National Lab. NM United States)
Goda, M. P.
(Universite Catholique de Louvain Belgium)
Date Acquired
August 19, 2013
Publication Date
June 30, 1997
Subject Category
Computer Systems
Report/Patent Number
DE98-000260
LA-UR-97-3456
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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