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Author Upfal, Eli ♦ Wigderson, Avi
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Copyright Year ©1987
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Abstract The power of shared-memory in models of parallel computation is studied, and a novel distributed data structure that eliminates the need for shared memory without significantly increasing the run time of the parallel computation is described. More specifically, it is shown how a complete network of processors can deterministically simulate one PRAM step in $\textit{O}(log$ $\textit{n}/(log$ log $\textit{n})2)$ time when both models use $\textit{n}$ processors and the size of the PRAM's shared memory is polynomial in $\textit{n}.$ (The best previously known upper bound was the trivial $\textit{O}(\textit{n})).$ It is established that this upper bound is nearly optimal, and it is proved that an on-line simulation of $\textit{T}$ PRAM steps by a complete network of processors requires $&OHgr;(\textit{T}(log$ $\textit{n/}$ log log $\textit{n}))$ time.A simple consequence of the upper bound is that an Ultracomputer (the currently feasible general-purpose parallel machine) can simulate one step of a PRAM (the most convenient parallel model to program) in $\textit{O}((log$ $\textit{n})2log$ log $\textit{n})$ steps.
ISSN 00045411
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1987-01-01
Publisher Place New York
e-ISSN 1557735X
Journal Journal of the ACM (JACM)
Volume Number 34
Issue Number 1
Page Count 12
Starting Page 116
Ending Page 127


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Source: ACM Digital Library