<html>
<head>
<style>
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
FONT-SIZE: 10pt;
FONT-FAMILY:Tahoma
}
</style>
</head>
<body class='hmmessage'>
Please pardon my naive questions but this is surely the place to get an expert answer. I am enthused by the recent micrWulf built by Prof. Adoms and his student at Calvin College. That device approached a "homogeneous" parallel system with all the same core frequencies and achieved over 26 GFLOPS for about $1200. With private funds and a curious 3 yo grandson I prefer to enclose the "System" into four PC cases and an external Ethernet switch. I also want to maintain the performance I now have with a 3 GHz Toshiba Pentium 4 laptop so I prefer an "asymmetric" system with a fast Master node with a lot of frills and three slower dual core satellite PCs. About ten years ago I was able to link an HP 9000/720 running HP-UX in one building with three other SGI nodes running IRIX in another building connected by TCP/IP Ethernet. Sadly I do not recall the name of that message passing system but the link was a pretty bad mismatch between the slower HP9000/720 and the faster SGI CPUs at that time but it was something with "Theoretical Chemists ......". Was that TCP/IP? Anyway I know it is possible to link CPU/cores with different speeds and different memory-bus speeds so my question is whether "Open MPI" can handle this situation? Specifically, suppose I set up:<BR>
<BR>
1. a Master box with an AMD X2 5800+ overclocked to 3.0 GHz with DDR2 800 memory (at least 4GB, maybe 8GB), 1 300 GB SATA drive; there would also be other creature comfort frills on the Master box like CD R/W, floppy drive, graphics card etc.<BR>
<BR>
2. three cheaper AMD X2 4000+ (2.1 GHz) and running cheaper DDR2 667 memory; bare bones, no drives just CPU, memory and gigE switch.<BR>
<BR>
3. connected by a Trendware TEG-S80TXE 8-port Gigabit Ethernet switch with associated NIC switches.<BR>
<BR>
If all the CPU/nodes/cores were AMD X2 4000+ units this should be similar to the Calvin College microWulf and run at about 27 GFLOPS (LINPAK) due to the slightly faster 2.1 GHz AMD 4000+ CPUs compared to the microWulf AMD 3800+ 2.0 GHz units. I do not seek the <BR>ultimate (GFLOP/$) minimum, just an inexpensive system to run GAMESS for molecular calculations and a chance to learn about parallel software late in my career.<BR>
<BR>
So, can "Open MPI" handle different CPU/core frequencies and different memory bus frequencies over gigE. I note that the writer of GAMESS (Mike Schmidt) recommends TCP/IP for GAMESS rather than OPEN MPI and GAMESS is the overwhelming goal for my use but using UBUNTU I would like to be able to access the Internet as well from the Master box. While I have your attention, could you comment on whether Open MPI will run under LINSPIRE? I have messed around with LINSPIRE more than UBUNTU (although I have both source disks) and I like LINSPIRE because it looks more like WINDOWS.<BR>
<BR>
Summary:<BR>
<BR>
1. Can Open MPI handle different clock speeds across several node/cores?<BR>
<BR>
2. Can Open MPI handle different memory bus clock speeds across several node/cores?<BR>
<BR>
3. Why not LINSPIRE instead of UBUNTU?<BR>
<BR>
Sorry about the dumb questions but I seem to recall that the Duke Beowulf managed to run using many different X86 PCs so what I want to do should be possible, but is Open MPI the best choice or what else?<BR>
<BR>
Don Shillady<BR>
Emeritus Professor of Chemistry, VCU<BR>
Ashland VA (working at home)<BR>
<BR> <BR>
<BLOCKQUOTE>
<HR>
Date: Wed, 28 Nov 2007 10:37:45 -0500<BR>From: peter.st.john@gmail.com<BR>To: charliep@cs.earlham.edu<BR>Subject: Re: [Beowulf] Really efficient MPIs??<BR>CC: beowulf@beowulf.org<BR><BR>
<DIV>For the sake of others as easily confused as myself, I note (now, thanks!) that OpenMP and OpenMPI are two different things:</DIV>
<DIV>OpenMP (an alternative to the MPI method) is <A href="http://en.wikipedia.org/wiki/OpenMP" target=_blank>http://en.wikipedia.org/wiki/OpenMP</A></DIV>
<DIV>OpenMPI (an implementation of MPI) is <A href="http://en.wikipedia.org/wiki/OpenMPI" target=_blank>http://en.wikipedia.org/wiki/OpenMPI</A></DIV>
<DIV>Cool.</DIV>
<DIV>Peter<BR><BR></DIV>
<DIV class=EC_gmail_quote>On Nov 28, 2007 8:49 AM, Charlie Peck <<A href="mailto:charliep@cs.earlham.edu">charliep@cs.earlham.edu</A>> wrote:<BR>
<BLOCKQUOTE class=EC_gmail_quote style="PADDING-LEFT: 1ex; BORDER-LEFT: #ccc 1px solid">
<DIV class=EC_Ih2E3d>On Nov 28, 2007, at 8:04 AM, Jeffrey B. Layton wrote:<BR><BR>> If you don't want to pay money for an MPI, then go with Open-MPI.<BR>> It too can run on various networks without recompiling. Plus it's <BR>> open-source.<BR><BR></DIV>Unless you are using a gigabit ethernet, Open-MPI is noticeably less<BR>efficient that LAM-MPI over that fabric.<BR><BR>I suspect at some point in the future gige will catch-up but for now <BR>my (limited) understanding is that the Open-MPI folks are focusing<BR>their time on higher bandwidth/lower latency fabrics than gige.<BR><FONT color=#888888><BR>charlie<BR></FONT>
<DIV>
<DIV></DIV>
<DIV class=EC_Wj3C7c>_______________________________________________<BR>Beowulf mailing list, <A href="mailto:Beowulf@beowulf.org">Beowulf@beowulf.org</A><BR>To change your subscription (digest mode or unsubscribe) visit <A href="http://www.beowulf.org/mailman/listinfo/beowulf" target=_blank>http://www.beowulf.org/mailman/listinfo/beowulf</A><BR></DIV></DIV></BLOCKQUOTE></DIV><BR></BLOCKQUOTE></body>
</html>