Newsgroups: ont.events
Path: utzoo!utgpu!jarvis.csri.toronto.edu!csri.toronto.edu!clarke
From: clarke@csri.toronto.edu (Jim Clarke)
Subject: U of Toronto graphics seminar, Jan. 31
Message-ID: <8901261941.AA03279@steeles.csri.toronto.edu>
Organization: University of Toronto, CSRI
Distribution: ont
Date: Thu, 26 Jan 89 14:41:48 EST


     GRAPHICS SEMINAR - Tuesday, January 31,  3 p.m. in  Room  GB 120
              (GB = Galbraith Building, 35 St. George Street)

                            Marie-Claire Forgue
                            Universite de Nice
                Laboratoire de Signaux et Systemes (LASSY).

           "Ray-tracing parallelization on a SIMD/SPMD machine"

The goal of this thesis is to implement a ray-tracing algorithm on the OP-
SILA vector/parallel machine. This machine offers two operating modes, SIMD
(Single Instruction Multiple Data) and SPMD (Single Program Multiple Data),
which coexist and cooperate. In our application, we used a mixed-mode pro-
gramming approach, using SPMD mode to perform calculations, and SIMD mode
to exchange information between processors. The communication protocol is
structured by use of ray-packets. We used vectorial indirect access primi-
tive called "Scatter" to perform the packet exchange. However, the use of a
synchronous interconnection network causes the phase of communication to be
delayed. Because of the unavoidable work disparity among processors, this
leads to a decrease in global efficiency.
-- 
Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
              (416) 978-4058
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