IDL memory allocation limitation

[rivers(at)cars3.uchicago.edu (Mark Rivers)]

I am having a problem with memory limitations in IDL on Windows NT which I do
not understand, and wonder if someone could help with.  I have 2 Windows NT
systems, "ferrari" and "lotus".  These systems are configured as follows:

                ferrari     lotus

# CPUs		2	    2
Clock speed	450	    750
RAM             1 GB        1 GB
Paging file     2 GB        2 GB
IDL             V5.3        V5.3
OS              NT 4.0      NT 4.0
NT Service Pack   4           6

Thus, the systems are basically identical except for the clock speed and NT
service pack.

My problem is in the amount of memory which IDL can allocate. The following
table shows the maximum size BYTE array which I can allocate in IDL.  This is
right after a system reboot, no other applications are running and this is the
first command entered in IDL.

            ferrari                 lotus
b = bytarr(1024, 1024, 1007)    b = bytarr(1024, 1024, 755)

Thus, on ferrari I can allocate essentially 1 GB of memory, which is the limit
for a single Windows NT process.  However, on lotus I can only allocate .75 GB.
Can anyone suggest why lotus would be limiting that maximum size array I can
allocate?  It is a serious problem for the applications I am running.

Thanks,
Mark Rivers