[daip] 32 bit vs. 64 bit

[Carl Gross]

Hello.  I am a radio astronomer at the Naval Research Lab and I have a
computing question.  Our group regularly uses AIPS to reduce VLA data.  We
have recently purchased two new workstations from Penguin Computing which
use the AMD Opteron processor.  The Opteron is a processor which can run in
either 32-bit or 64-bit mode.  I understand that there may be small
reliability issues with running AIPS in 64-bit mode.  Penguin Computing tech
support tells me that the decision to run in 32-bit or 64-bit mode is made
by each application on the computer, and not by a BIOS or other system
setting.  My question is:  Does AIPS have some control over whether it runs
in 32-bit mode or 64-bit mode?  If so, what are the control parameters and
how do I use them?  If not, do you know of another method which might
instruct AIPS to run in 32-bit mode?  We are running Redhat Enterprise
version 4 on each machine.  I briefly nosed around the AIPS website for such
information but could not find any.  If there is any documentation that I
may have missed regarding this issue, please direct me there.

Thanks for your time,

Carl Gross
Naval Research Lab