Warp schrieb:


>> And thats the point. A 64Bit-compile on an AMD64 box will increase the 
>> performance of POVRay. If this increase of performance is caused by the 
>> 64-bitness or the increased number of (SSE) registers is meaningless. It 
>> _will_ be faster. Thats the point.
> 
>   No, I don't think that was the point.

So I see we understand the original posting in a different way.

>   The original question was: "Has anyone tried to compile 3.5 with 64bit
> optimizations?"

And goes on with: "I have a new PC with an AMD64 3200+ cpu (running 
Windows XP64)" So the processor we talk about has AMD64 extensions.

>   From my part I can answer: Yes, I have tried. It didn't give any
> speed benefits. In fact, it was some percents slower than the 32-bit
> version. (More specifically, I have tried it with an UltraSparc processor
> which supports both 32-bit and 64-bit binaries.)

The same for AMD64 here under Linux. Running 32Bit and 64Bit binaries.

>   If the question had been "has anyone tried to compile an AMD64-optimized
> version of POV-Ray" that would have been a different thing.

I understand the question in that way because the OP has telled us which 
hardware he is using.

>> And so a version of POVRay for 
>> WindowsXP 64Bit edition will bring advantages against a 32 Bit Version.
> 
>   That depends on the CPU you are using. That statement of yours seems
> to imply that a version compiled for a 64bit edition of WindowsXP will
> automatically be faster, period, *regardless of the processor used*.

Because WindowsXP 64Bit Edition supports only one processor-architecture 
(namely AMD64 or x86-64) there are no different processor architectures.

> That's not true. The OS doesn't matter, it's the CPU which matters.

Right.

>   Could we *please* stop widespreading false concepts? If you keep
> claiming that "a 64-bit version of POV-Ray will be faster than
> a 32-bit version" without any further details, you are just giving
> misconceptions to people. People are going to think that there's
> something magic in the 64-bitness which POV-Ray can benefit from
> for extra speed.

You are right here. Let me correct it:
A 64-bit version on AMD64 will be faster than a 32-bit version on AMD64.


-- 

mat### [at] matweide
http://www.matwei.de

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