Memory

[Raghubhushan Pasupathy]

Hello Folks,

I am running a sixteen processor  (8 duals with SMP, 256MB memory) cluster 
in the School of Civil Engineering, Purdue. Here is my problem:

I run a Fortran program sequentially on a single processor and I am able to 
define more than 30 arrays, 900,000 elements (integer) in size without the 
machine swapping. In fact, this is still not my upper limit. However, when I 
run this code parallely (MPI) on two processors in the same machine, I am 
unable to go beyond a 6000 array size. I get a "signal 11" and much before 
that the machine starts swapping.

My question is: The numbers do not add up at all. Even if I duplicate all 
the arrays for the second process, the machine should easily be able to 
handle more than 30 arrays of 6000 elements. I do not understand what is 
going on.

Any help would be much appreciated.

Raghu


Raghu Pasupathy
School of Civil Engineering
Purdue University
West Lafayette, IN 47906

(765) 494 2206 (off)
(765) 495 6470 (res)
rpasupathy at hotmail.com


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