On Mar 5, 2009, at 1:29 PM, Jeff Squyres wrote:
On Mar 5, 2009, at 1:54 AM, Sangamesh B wrote:
The fortran application I'm using here is the CPMD-3.11.
I don't think the processor is Nehalem:
Intel(R) Xeon(R) CPU X5472 @ 3.00GHz
Installation procedure was same on both the clusters. I've not set
mpi_affinity.
This is a memory intensive application, but this job was not using
that much amount of memory.
Regarding CPU & ELAPSED TIMEs, the CPU TIME should be greater than
ELAPSED TIME in general (for a parallel program). Right?
It depends on exactly what you're reporting for ELAPSED time. Is
that wall clock time? Or user time? Or something else?
Ralph and I disagree on this point, but my opinion is that the only
meaningful time reported in a parallel application is the wall clock
time. The CPU time can be badly skewed by a variety of things, such
as any filesystem IO, network activity (depending on whether you
have an OS-bypass network or not), etc.
You have gradually worn me down on this point... :D
--
Jeff Squyres
Cisco Systems
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