Strange memory limits

Hi,

I have been chasing a problem for the last couple of days
that has me
stumped. I am running SLES9 on a POWER machine with around
30 gigs of ram. I
want to run some analysis processes that will take up about
10 gigs of ram
each. However, for some reason processes are running out of
memory at the
3.7 gig mark on this machine. Actually, Python procs run out
at 2.1 gigs and
C programs start getting ENOMEM errors at 3.7 gigs. I don't
have any per
process memory limits set and this problem has me baffled.
Any insight would
be much appreciated.

Thanks.

--Narayan Newton