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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>Dear Wien Users,</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial size=2>I'm running WIEn2k on a 16 node beowulf
cluster with two CPUs per node. </FONT></DIV>
<DIV dir=ltr>All nodes have a common NFS.</DIV>
<DIV dir=ltr><FONT face=Arial size=2>When I run several parallel jobs (about 3
or 4 jobs at a time using </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>4 nodes per job), lapw1 scales almost
</FONT><FONT face=Arial size=2>linearly in parallel </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>but parallel lapw2 ( and sometimes lapwso)
is way slower, </FONT><FONT face=Arial size=2>compared to </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>a single node.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial size=2> For example, lapw2 takes about 45
seconds on </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>a singe node but for 4 nodes it can take as
long as 15 minutes. </FONT></DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>I should state that I submit the jobs via PBS so all processes
</DIV>
<DIV dir=ltr>for a given job (lapw0, lapw1, lapw2 e.t.c.) are confined to</DIV>
<DIV dir=ltr>a particular set of nodes so jobs do not interfere.</DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr><FONT face=Arial size=2>I find this quite confusing.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>I've run several cases and </FONT><FONT
face=Arial size=2>this fact is </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>consistently true. </FONT><FONT face=Arial
size=2>Is there any way that I can constrain lapw2 </FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>to run in serial mode whiles lapw1
runs in parallel?</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial size=2>Thanks</FONT></DIV>
<DIV dir=ltr><FONT face=Arial color=#000000 size=2></FONT> </DIV></DIV>
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<DIV><FONT face=Arial color=#000000 size=2>R.
Atta-Fynn</FONT></DIV></DIV></FONT></DIV>
<DIV dir=ltr><FONT face=Arial color=#000000 size=2></FONT> </DIV></DIV>
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