Nieminen Mika wrote:
> 
> Ken <tyl### [at] pacbellnet> wrote:
> : The official home of the Povray benchmarks is at:
> : http://www.haveland.com/povbench/
> 
>   I still think that this benchmark has not very much relevance anymore with
> current computers. If one computer renders the skyvase in 5 seconds and
> other in 6 seconds, that doesn't tell anything about which one is faster.
> When we talk about times this short, you can't compare computers anymore.
>   If you render the scene for first time it may take 10 seconds. If you then
> render it again, it may take 5 seconds. Is the computer twice as fast now?
> Of course not. There are several things that affect the render time
> significantly when the total time is so short, for example the disk buffer,
> cache, other processes, etc. You can get very varying times from one
> render to another. They have no meaning. One computer may be even faster
> than other even if it takes 10 seconds to render the skyvase although the
> other one takes only 5. Perhaps the other one had a faster disk or whatever.
>   If the scene was so slow to calculate that it took about 1 minute for
> the fastest computer to render it, then the results could be relevant. Then
> the time really measures rendering speed. If a poor disk cache adds a couple
> of seconds to the total time, that has no meaning when the total time is
> over one minute.
> 
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

I think you can eliminate the disk cache from the equation because the file
and memory overhead is so small that the scene easily loads into ram memory
even on the most poorly equipped machines. With regard to other elements
effecting render times I agree that a more robust scene should be developed
to really test the power of modern processors and ultimately their true
raytracing speed rating. I leave that task to those more competent than
myself to decide what that may be but I'm sure there must be some routines
in Pov that could be used for a reliable benchmark. Probably a combination
of math functions, high order primitives, and complex surface finishes that
require large numbers of ray intersection tests. All of this can still be
done without the need to consume large quantities of memory so that disk
swapping can be avoided on even under equipped machines.

-- 
Ken Tyler

See my 700+ Povray and 3D Rendering and Raytracing Links at:
http://home.pacbell.net/tylereng/index.html

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