I've run benchmarks on my computer comparing 64-bit povray vs. 32-bit
povray. See for yourself:

sempron 1.6 GHz 32-bit kernel, 32-bit povray, sse2
Total Time:    0 hours 34 minutes  41.0 seconds (2081 seconds)

sempron 1.6 GHz 64-bit kernel, 32-bit povray
Total Time:    0 hours 36 minutes 41 seconds (2201 seconds)

sempron 1.6 GHz 64-bit kernel, 64-bit povray gcc 3.4
Total Time:    0 hours 29 minutes 27 seconds (1767 seconds)

duron 1.6 GHz
Total Time:    0 hours 40 minutes  46.0 seconds (2446 seconds)

So there you go: a 17.7% increase in rendering time on the benchmark scene.
Of course, as others have pointed out, there probably won't be a speedup on
architectures that were 64-bit to begin with.

Post a reply to this message

Warp wrote:
> 
>   I was just asking, out of curiosity, what is it that makes some people
> believe that a 64-bit system should/might be twice as fast (or just faster
> by some degrees) than an equivalent 32-bit system.
> 

It has lately been common to explain that the CPU MHz doesn't actually
tell the speed of the computer, but just part of it. While most PC-users
has never heard of eg. Sun Ultrasparcs, the AMD64 is the first 64-bit
system to them. And like you said, it has a bunch of features to run
faster. Optimizing in 64-bit mode, yes, but also eg. the integrated
memory controller. Opteron handles memory a _lot_ faster than same aged
Xeon.

That's one thing to make 64bit faster than 32bit - in people's mind.
Just my 2 cents.


-- 
Eero "Aero" Ahonen
   http://www.zbxt.net
      aer### [at] removethiszbxtnetinvalid

Post a reply to this message

Darren New wrote:
> 
> Analogies with other things that work that way, like a V-8 engine having
> twice the acceleration than a 4-banger.

Which is also poop ;).

-- 
Eero "Aero" Ahonen
   http://www.zbxt.net
      aer### [at] removethiszbxtnetinvalid

Post a reply to this message

Thomas de Groot <t.d### [at] internlnet> wrote:
> Well, just because I feel it is a waste of time for me.

  Information is never a waste of time.

-- 
                                                          - Warp

Post a reply to this message

Warp wrote:
> Thomas de Groot <t.d### [at] internlnet> wrote:
> 
>>Well, just because I feel it is a waste of time for me.
> 
> 
>   Information is never a waste of time.
> 

It also may be a waste of other resources, too.

-- 
Eero "Aero" Ahonen
   http://www.zbxt.net
      aer### [at] removethiszbxtnetinvalid

Post a reply to this message

"Warp" <war### [at] tagpovrayorg> schreef in bericht 
news:44d60ead@news.povray.org...
> Thomas de Groot <t.d### [at] internlnet> wrote:
>> Well, just because I feel it is a waste of time for me.
>
>  Information is never a waste of time.
>

True. I agree. But if you lack the knowledge to appreciate particular 
information, then it becomes random noise so to speak :-)

What I mean is that instead of spending (precious) time struggling through 
information I do not really understand, I prefer to concentrate upon what I 
need to do. Time is short...

Thomas

Post a reply to this message

Thomas de Groot <t.d### [at] internlnet> wrote:
> What I mean is that instead of spending (precious) time struggling through 
> information I do not really understand, I prefer to concentrate upon what I 
> need to do. Time is short...

  And then, when you don't have even the most basic information, you make
all kinds of wrong assumptions, mistakes and, in the worst case, a fool
of yourself.

  Basic information is never useless.

-- 
                                                          - Warp

Post a reply to this message

"Warp" <war### [at] tagpovrayorg> schreef in bericht 
news:44d725db@news.povray.org...
>
>  And then, when you don't have even the most basic information, you make
> all kinds of wrong assumptions, mistakes and, in the worst case, a fool
> of yourself.
>
>  Basic information is never useless.
>

That also is true. Except for the fool, as I believe that one should not 
peremptorily offer advice about things one does not know anything about. But 
asking questions or even making wrong assumptions is never foolish.

Still, I do not want to know how my car does what it does (I mean: 
transporting me from A to B and back again)... :-)

Thomas

Post a reply to this message

Warp nous apporta ses lumieres en ce 01/08/2006 17:31:
> Alain <ele### [at] netscapenet> wrote:
>> both 32 and 64 bits CPUs use 64 bits FPUs
> 
>   Actually Intel (and compatible) processors use 80-bit floating point
> numbers internally. I don't know why, but they just do.
> 
OK then. So, as long as your results STAY in the FPU and you keep on reusing 
them, you can keep an improved acuracy. But, as soon as you need to put your 
results anywhere else, you fall back to 64 bits acuracy. Would be good if you 
could preserve those extra 16 bits. This would open up double and half precision 
FP numbers.

-- 
Alain
-------------------------------------------------
SHOPPING MATH
A man will pay $20 for a $10 item he needs.
A woman will pay $10 for a $20 item that she doesn't need.

Post a reply to this message

Tim Cook nous apporta ses lumieres en ce 02/08/2006 00:49:
> So what's all the hubbub over 32-bit processors?  Aren't they slower 
> than 16-bit CPUs in exactly the same way as 64s are to 32s?  It just 
> take longer to assign anything and nothing needs the precision other 
> than some specialized applications.  Besides, nobody needs more than 640 
> kB of RAM...
> 
> *wink*
> 
The early 32 bit processors where indead a bit slower than contemporary 16 bit 
ones. Also, early 32 bit programms where almost always slower than 16 bit 
versions when running on the same 32 bit processor. It's worth noting that 
almost all 16 bit processors had at least 20 bit address bus, up to maybe 32 for 
the latest. Also, ALL 8 bit CPU had 16 bit address path before the 8086 (20 bit 
address space).

-- 
Alain
-------------------------------------------------
You can go anywhere you want if you look serious and carry a clipboard.

Post a reply to this message