Date: Mon, 28 Oct 2002 19:41:15 -0800
From: "David A. Case"
Subject: Re: 64-bit Compilation SUN's forte compiler

On Mon, Oct 28, 2002, Scott Brozell wrote:
>
> Generally, a 64 bit addressable executable is only recommended for
> applications that require the extra addressing space because a
> 32 bit addressable executable will have superior performance by a
> couple of percent.

In my experience, there are some cases for sander where -n32 is quite a bit
faster than -64 on SGI processors. This is why we have specified -n32
compilation, even for machines where the default is -64. I don't have
details handy right now, but there are only a few, pretty unusual, situations
where sander requires 64 bit addressing. Nmode, is another story, and
we often compile 64-bit versions in order to do normal mode analysis.

..hope this helps...dac