[Pw_forum] Memory question

[Miguel Martinez]

Hello everybody,

I'm running parallel espresso (v2.1.5) in an Itanium2 cluster. The OS is 
Red Hat Linux, and the kernel is 2.4.20. The cluster uses mpich 1.2.6, 
and the jobs are sent using PBS. Compiler is Intel v7. Most nodes use 
4Gb, though there are some with 16Gb RAM.

The thing is that, when I send a phonon multiprocessor run, while it 
doesn't use a lot of memory (some 250Mb per thread), it swaps out. I've 
run two proccessors in a 4 proc node and, to make sure other jobs don't 
interfere, using all 4 procs for myself.

1) Is it normal that, while it could empty memory from older jobs, my 
phonon runs are swapping?

I personally haven't seen this on my laptop (gfortran instead of ifc)... 
but I only do low cutoff and kpoints runs in my laptop.

2) Will this affect performance badly? Or are phonon runs more 
restricted by i/o speeds?

3) This is a bit off topic. Is it OK to use -npools while using 
processors in the same node or is it dumb?

Thank you very much for your time,

Miguel


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Miguel Martínez Canales
Dto. Física de la Materia Condensada
UPV/EHU
Facultad de Ciencia y Tecnología
Apdo. 644
48080 Bilbao (Spain)
Fax:  +34 94 601 3500
Tlf:  +34 94 601 5437
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  "UNIX was not designed to stop its users from doing
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Doug Gwyn