Arvind Gopu wrote:
>John-
>
>I don't know if your problem is build/platform specific, but we run LAM
>jobs on multiprocessor (two to be precise) nodes all the time without any
>problems. Intel Prestonia, RHEL 3, LAM 7.1.1 and 7.1.2beta.
>
>It's another issue, though, that the performance takes a big hit when I
>use both processors on the same node. That behavior is common to LAM and
>MPICH (on our system) and we've thought about a whole bunch of possible
>reasons.
>
>
>
Are you raising a new topic, with a top post on a thread? It's
entirely possible for the first process on a node to tie up the memory
system, leaving no gain for the 2nd process. If you don't have enough
RAM, or (since yours appears to be a 32-bit system) enough address space
for 2 processes, this is nearly guaranteed.
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