Newsgroups: comp.parallel.pvm
From: wjiang@thud.cs.utk.edu (weicheng jiang   )
Subject: Re: Q's about Paragon and PVM
Organization: Computer Science Dept, University of Tennessee, Knoxville
Date: 9 Sep 1995 20:56:40 GMT
Message-ID: <42sv28INNa5i@CS.UTK.EDU>

In article <42phvk$grl@moon.src.honeywell.com>, vanvoors@boreas.src.honeywell.com (Brian VanVoorst) writes:
|> I am interested in understanding more about other people's experience using
|> PVM on the Paragon and how PVM is implemented on the Paragon.
|>  
|> Let me say that I already know that PVM is going to perform poorly on the
|> Paragon, but I am required to get some timings of an application implemented
|> with PVM on the Paragon so that is just the way things are.
|>  
|> It's a simple application and when it runs using NX (the Paragon's native
|> communication lib) on four nodes it take about 9 seconds, the send
|> side communication cost is about 2% of that.
|>  
|> When the code is ported to PVM (the communication is simple, it's a direct
|> port), it takes about 81 seconds.  Now, I expected the communication to be
|> much much slower, but it isn't THAT slow.
|>  
|> I have a bunch of questions floating around my head, if anyone has any
|> answers they would like to offer please respond.
|>  
|>    What is happening that is making it so slow?
|>       ... Is there a PVM daemon on each node that is swapped in from disk
|>             for every communication?
|>       ... How does PVM on the Paragon work?
|>  
|>    What are other peoples experience with PVM on the Paragon?
|>       ... Do other people get these performance problems that are above and
|>            beyond what you would expect for communication overhead?
|>       ... Is there a real code that got good performance that I can look at?
|>  
|>    Are there any papers out there on PVM on the Paragon that I should find?

Check out the paper at

	http://www.netlib.org/utk/papers/pvmmpp/pvmmpp.html

Should be a good starting point.

-Weicheng Jiang
PVM Group, University of Tennessee

