POV-Ray : Newsgroups : povray.general : POV render time w/ better PC????? Server Time
5 Nov 2024 03:18:59 EST (-0500)
  POV render time w/ better PC????? (Message 1 to 3 of 3)  
From: Greg M  Johnson
Subject: POV render time w/ better PC?????
Date: 6 Dec 1998 15:09:08
Message: <366AE4B6.F46B7E7B@aol.com>
I just purchased a new PC.

My OLD PC is an Aptiva with 64MB RAM and a 200 MHz Pentium.
My NEW PC is an Aptiva with 256 MB RAM and a 450 MHz Pentium II.

I compared the render times for three different scene files.  One was
with Bryce, and involved transparent and reflective objects. The other
two were in POV-Ray.  One was a human character made out of blobs of my
own creation.  The other was the LATHE2.POV file that is found in the
POVDEMO directory shipped with version 3.02

Render times in min:sec

                      OLD PC   NEW PC
Bryce scene    29:30        2:49
POV, blobs      0:29         0:11
POV, lathe2     9:01         4:16

What gives?  With Bryce, I get a 10X improvement in render time, but POV
gives me less than a 3X improvement!  Does this point to some other
"hardware" solution to a faster POV render? Could this point to a
problem with my PC: dead memory, etc.?


___________________________
Greg M. Johnson
http://members.xoom.com/gregjohn


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From: Steven Pigeon
Subject: Re: POV render time w/ better PC?????
Date: 6 Dec 1998 15:26:54
Message: <366AE8A8.128281E4@iro.umontreal.ca>
Greg M. Johnson wrote:

> I just purchased a new PC.
>
> My OLD PC is an Aptiva with 64MB RAM and a 200 MHz Pentium.
> My NEW PC is an Aptiva with 256 MB RAM and a 450 MHz Pentium II.
>
> I compared the render times for three different scene files.  One was
> with Bryce, and involved transparent and reflective objects. The other
> two were in POV-Ray.  One was a human character made out of blobs of my
> own creation.  The other was the LATHE2.POV file that is found in the
> POVDEMO directory shipped with version 3.02
>
> Render times in min:sec
>
>                       OLD PC   NEW PC
> Bryce scene    29:30        2:49
> POV, blobs      0:29         0:11
> POV, lathe2     9:01         4:16
>
> What gives?  With Bryce, I get a 10X improvement in render time, but POV
> gives me less than a 3X improvement!  Does this point to some other
> "hardware" solution to a faster POV render? Could this point to a
> problem with my PC: dead memory, etc.?

No, not really. POV is float-intensive, and the speed up is proportionnalto the
processor speedup
(p2 has better fpu, about 30% faster at equal
mhz, 2.5 times the mhz on the new machine 1.3 x 2.5  = 3.25, which is
consistant with the observed speedup).

As for Bryce, I'd guess it is memory-intensive, so that it stops swapping
with 256 megs of ram. It's a bit like loading netscape on a 200 mhz machine
with 16 megs of ram... and then on a 200 mhz machine with 128. It can't
be compared. Netscape takes about 5 sec to load on my machine (a 333mhz
with 128 meg of ram)... and about 30 sec on a pentium 90 with 32 megs of
ram. ... To tell the truth, I don't use Bryce, so I can't tell the reasons. May-
be it is also sensitive to the kind of video adapter you have. Going from a
mach 64 to a 3d Rage+ II _does_ make a lot of difference.

> ___________________________
> Greg M. Johnson
> http://members.xoom.com/gregjohn

Best,

    S.

--
----------------------------------------------------------
Steven Pigeon                     Ph. D. Student.
University of Montreal.
pig### [at] iroumontrealca           Topics: data compression,
pig### [at] jspumontrealca          signal processing,
ste### [at] researchattcom           non stationnary signals
                                  and wavelets.
----------------------------------------------------------
         http://www.iro.umontreal.ca/~pigeon


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From: Greg M  Johnson
Subject: Re: POV render time w/ better PC?????
Date: 7 Dec 1998 14:34:09
Message: <366c2db1.0@news.povray.org>
Steven Pigeon wrote:
> .....POV is float-intensive, and the speed up 
> is proportionnal to the processor speedup (p2 has better fpu, 
> about 30% faster at equal mhz, 2.5 times the mhz on the new
> machine 1.3 x 2.5  = 3.25, which is consistant with the 
> observed speedup).
> As for Bryce, I'd guess it is memory-intensive, so that it 
> stops swapping with 256 megs of ram. 

Which begs the question, could a future improvement of POV be to make it
more "memory-intensive"?

If the question is a dumb one, please forgive me.  I'm an expert (IMHO)
in the materials science behind manufacture of ceramic packaging for
chips, but am quite ignorant of how computers actually work. But could
it be that POV is "using up float-processor space" for things that could
be shoved over to the "memory"?   

Also, I think I would have noticed a whole lot of hard disk drive
activity if the old Bryce were swapping out, wouldn't I have? 
 
> Greg M. Johnson wrote:
> 
> > Render times in min:sec
> >
> >                OLD PC   NEW PC
> > Bryce scene    29:30    2:49
> > POV, blobs      0:29    0:11
> > POV, lathe2     9:01    4:16


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