Newsgroups: comp.parallel.pvm
From: mehra@ptolemy.arc.nasa.gov (Pankaj=Mehra)
Subject: Re: performance hit across subnets
Organization: Recom Technologies Inc.
Date: Fri, 4 Nov 1994 23:49:57 GMT
Message-ID: <1994Nov4.234957.19259@ptolemy-ethernet.arc.nasa.gov>

Using PVM-AIMS to monitor and visualize message passing, I have noticed
that messages that go through routers (across subnets) can often take
twice (or more) as long as messages within the subnet.

And, IMHO, the probability of collisions is higher if a message must be
transmitted over two different subnets than what it would be for messages
within the subnet.

In fact, one of AIMS' views is dedicated to showing you the underlying
subnet topology of your virtual machine. It clearly shows subnets, routers
and gateways as well as what machine is on what subnet(s).


-- 
-Pankaj Mehra
________________________________________________________________________________
415/604-0165 Recom Technologies (NASA-Ames, code FIC) mehra@ptolemy.arc.nasa.gov

