Newsgroups: comp.os.parix
From: Jamal.Zemerly@dcs.warwick.ac.uk (Jamal Zemerly)
Subject: PVM 3.2.3 on PARIX
Keywords: PVM
Organization: Department of Computer Science, Warwick University, England
Date: Tue, 6 Jun 1995 12:09:04 GMT
Message-ID: <1995Jun6.120904.3262@dcs.warwick.ac.uk>

Does anybody know how the multicast call in pvm 3.2.3 (pvm-mcast)
is implemented on the PARIX 1.2. I contacted Parsytec about this
last week but yet to receive an answer from them. Since this is
urgent I appreciate if somebody here knows how the multicast is
implemented. What I need to know specifically is whether it is
a one (the sender) to all (e.g. 1->2, 1->3,  etc.) communications
or a neigbour-to-neighbour (e.g. 1->2, 2->3, etc.) or something
else other than the above. The reason I need to know this is
to be able to predict the multicast time using a summation of all
point-to-point communications executed rather than fit a model to
the measurements which can be quite erroneous for small number of
processors. I know that multicast is asynchronous but I need to 
predict the time it takes for the message to reach the last 
processor on the grid. We have a Parsytec SuperCluster with 128
T800s. Any help is much appreciated.

Jamal Zemerly

jamal@dcs.warwick.ac.uk

