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On 5/25/07, burlingk@×××××××××.mil <burlingk@×××××××××.mil> wrote: |
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> |
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> > -----Original Message----- |
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> > From: Randy Barlow [mailto:randy@×××××××××××××××××.com] |
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> |
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> <Snip> |
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> |
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> > If you are using a lot of memory in your computations, then |
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> > the 64-bit environment will be much friendlier to you :) |
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> > Also, if I understand correctly, you will get higher |
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> > precision on floating point calculations (someone correct me |
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> > if I am wrong here!) I also believe that the 64 bit |
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> > processors are able to perform more instructions per second |
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> > on average when executing 64 bit code vs. 32 bit code if I am |
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> > not mistaken... |
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> |
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> I am not sure, but that makes sense. If nothing else, things executed |
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> directly usually run more smoothly than those who are run through |
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> emulation. 64bit code on 64bit processor good... |
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There is no emulation involved when running 32bit code in either core2 |
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nor amd64 processors. The difference when running in 32bit mode is |
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that some instructions are unavailable, you have a smaller number of |
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registers, and the registers are only 32bit. |
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More registers speed up most kind of code, 64bit registers speed up |
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64bit calculations, and the extra instructions are good for array |
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calculations and similar (more sse instructions for example). |
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The only bad thing with 64bit code is that the programs get bigger, |
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which may effect memory performance negatively. But if you have a lot |
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of memory then you will benefit from not needing any special |
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addressing modes. |
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Since you (Denis) are doing a lot of mathematical calculations you |
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will probably benefit from running in 64bit mode. |
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-- |
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