[Wien] lapw2para very slow

[Atta-fynn, Raymond]

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