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From: Jun Sun <jsun@mvista.com>
To: Dennis Castleman <DennisCastleman@oaktech.com>
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In-Reply-To: <56BEF0DBC8B9D611BFDB00508B5E2634102F10@TLEXMAIL>; from DennisCastleman@oaktech.com on Thu, Apr 17, 2003 at 10:53:57AM -0700
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On Thu, Apr 17, 2003 at 10:53:57AM -0700, Dennis Castleman wrote:
> ALL
> 
> Anybody know the performance differences I can expect using a MIPS 5K core
> @250 Mhz in 64bit mode versus 32bit mode?
>

It really depends on the applications.  The biggest gain from 64bit,
other than the obviously bigger address space, is 64bit data
manipulation.  A single 64bit instruction (add/sub/...) is carried
out by several instructions in 32bit.

If your apps are heavy on 64bit operations, then you gain.
Otherwise I suspect no performance gain or even possibly a little 
worse performance due more stress on cache/memory subsystems.

I am sure others with more 64bit experience probably have more 
to say.  :)


Jun