POV-Ray : Newsgroups : povray.general : Real benefit of a 64 bit Pov binary on a 64 bit CPU in a 64 bit opsys? : Re: Real benefit of a 64 bit Pov binary on a 64 bit CPU in a 64 bit opsys? Server Time
1 Aug 2024 04:15:14 EDT (-0400)
  Re: Real benefit of a 64 bit Pov binary on a 64 bit CPU in a 64 bit opsys?  
From: Alain
Date: 31 Jul 2006 19:16:54
Message: <44ce8f66@news.povray.org>
Mike Sobers nous apporta ses lumieres en ce 31/07/2006 18:43:
> Warp <war### [at] tagpovrayorg> wrote:
>> Mike Sobers wrote:
>>    How the heck could it do that?
> 
> Well, I don't know.  I'm not an OS programming expert.  Maybe it's not
> possible, but in any case it's probably unlikely that an OS would be
> designed to operate this way, since dual 32-bit processors would be more
> efficient I would think.  Mathematically, you could use the upper 32 bits
> of a 64-bit memory allocation simultaneously with the lower 32-bits by
> shifting the information in the registry upward.  That way one 64-bit
> operation could accomplish two 32-bit operations.  Whether this is useful
> in a larger programming sense, I don't know, but I suspect not otherwise
> programmers would take advantage of it. While 64-bit generally means more
> _precision_ in the calculations, a program could utilize the extra memory
> capacity available to each 64-bit operation to accomplish two 32-bit
> operations at the same time.
> 
> Your question was "why do some people think it could be twice as fast?".
> It's because some people understand math and binary operations, but not
> neccessarily how computer architecture is designed around them.  That's why
> the question was asked in the first place, because a lot of us have a lot to
> learn about what advantages the new higher-precision hardware/software will
> provide.
> 
> Mike
> 
> 
> 
You can have more precision in integer calculations. You can do 64 bits add in 
one operation while you need to emulate it on a 32 bits CPU. BUT when you do 
floating point operations, both 32 and 64 bits CPUs use 64 bits FPUs, you may 
gain a little speed while transmiting the operands and retriving the results, 
but it's prety slim. Normaly, you do hundreds, even thousands, more FP 
calculations than INT ones.

-- 
Alain
-------------------------------------------------
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person you may be the world.


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