POV-Ray : Newsgroups : povray.advanced-users : Memory access limits Server Time
1 Nov 2024 19:14:59 EDT (-0400)
  Memory access limits (Message 1 to 8 of 8)  
From: David Wallace
Subject: Memory access limits
Date: 5 May 2004 19:39:52
Message: <40997b48$1@news.povray.org>
How much memory (virtual or ortherwise) can POV-Ray consume before it fails?
I have a very involved scene (radiosity, 22.9 MB in parametric meshes, major
water effects requiring max_trace 11).  I am getting a "failed to allocate
display bitmap" error which aborts the render.

I am running an Athlon XP 2000, 1 GB PC3200, Windows 2000 Pro SP4.

This scene has stuffed every computer I've thrown at it since October 2001,
when I first designed it for the IRTC.  It's first victim was a Duron 800
with 256 MB under Windows 98SE and I bought another 256 MB stick just for
this application at the time and still nothing.

What is going on behind the scenes that is preventing this scene from
working?
-- 
David Wallace
TenArbor Consulting
"Just In Time Cash"
www.tenarbor.com


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From: Christoph Hormann
Subject: Re: Memory access limits
Date: 6 May 2004 02:55:02
Message: <c7cnat$2bj$1@chho.imagico.de>
David Wallace wrote:
> How much memory (virtual or ortherwise) can POV-Ray consume before it fails?

Infinite.

Well, not really of course but your OS will give up much earlier than 
POV-Ray.

Since the error message you mention is about the display bitmap the 
first thing to try would be rendering without display (-d).

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 01 May. 2004 _____./\/^>_*_<^\/\.______


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From: Warp
Subject: Re: Memory access limits
Date: 6 May 2004 05:00:51
Message: <4099fec2@news.povray.org>
Christoph Hormann <chr### [at] gmxde> wrote:
> > How much memory (virtual or ortherwise) can POV-Ray consume before it fails?

> Infinite.

> Well, not really of course but your OS will give up much earlier than 
> POV-Ray.

  Actually POV-Ray having been compiled as a 32-bit binary can allocate
at most 4 gigabytes (in practice probably 2 gigabytes) of memory. A system
can have that much memory available (if not with physical RAM, with
additional swap space). POV-Ray will fail to allocate more even if there
would be more.

  Of course in a 64-bit system with a 64-bit binary matters are a bit
different. (It can allocate at most 16 exabytes of memory, which is
quite a lot.)

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -


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From: Christoph Hormann
Subject: Re: Memory access limits
Date: 6 May 2004 07:40:02
Message: <c7d826$4rn$1@chho.imagico.de>
Warp wrote:
> 
>   Actually POV-Ray having been compiled as a 32-bit binary can allocate
> at most 4 gigabytes (in practice probably 2 gigabytes) of memory. A system
> can have that much memory available (if not with physical RAM, with
> additional swap space). POV-Ray will fail to allocate more even if there
> would be more.

Good luck with trying to use 4GB of memory (no matter if physical or 
not) on a (32bit) Windows system.  In theory a 32bit OS can also handle 
more than 4GB of memory so the limit would be indeed the application but 
in reality most Windows versions limit applications to 2GB, some server 
variants allow 3GB IIRC.

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 01 May. 2004 _____./\/^>_*_<^\/\.______


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From: Warp
Subject: Re: Memory access limits
Date: 6 May 2004 07:49:15
Message: <409a263b@news.povray.org>
Christoph Hormann <chr### [at] gmxde> wrote:
> In theory a 32bit OS can also handle 
> more than 4GB of memory so the limit would be indeed the application

  If I'm not completely mistaken, you can have up to 16 or 64 gigabytes
(I don't remember which) of physical RAM in a pentium or newer processor.
Of course one process can address only 4 gigabytes at a time. (To be able
to use all the memory the processor provides a memory paging system.)

  So indeed, you could even have more than 4 gigabytes of physical RAM,
yet a 32-bit POV-Ray binary could only allocate 4 gigabytes of it at most
(if the OS allows it).

-- 
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}//  - Warp -


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From: Christoph Hormann
Subject: Re: Memory access limits
Date: 6 May 2004 08:15:02
Message: <c7da76$56s$1@chho.imagico.de>
Warp wrote:
> Christoph Hormann <chr### [at] gmxde> wrote:
> 
>>In theory a 32bit OS can also handle 
>>more than 4GB of memory so the limit would be indeed the application
> 
> 
>   If I'm not completely mistaken, you can have up to 16 or 64 gigabytes
> (I don't remember which) of physical RAM in a pentium or newer processor.
> Of course one process can address only 4 gigabytes at a time.

This is what i meant with 'in theory'.  This is possible but only with 
proper support from Hardware, OS and applications.

And as said in reality the limit is below the 4GB address space limit in 
most cases.  For Windows you can find some more informations and 
available 'solutions' on:

http://www.brianmadden.com/content/content.asp?id=69

Christoph

-- 
POV-Ray tutorials, include files, Sim-POV,
HCR-Edit and more: http://www.tu-bs.de/~y0013390/
Last updated 01 May. 2004 _____./\/^>_*_<^\/\.______


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From: David Wallace
Subject: Re: Memory access limits
Date: 12 May 2004 03:03:58
Message: <40a1cc5e@news.povray.org>
I have since discovered that one of my objects had a large number of light
sources on lampposts.  Most of the memory consumption was in the light
vistas even though they were spotlights.  Since each lamp had 4 light
sources, I was able to use area_light spotlights to cut this figure by 75%.

That gave me the memory room for the bitmap, but the render still stuffs up
on the radiosity.  It will render (in about 36 hours) without radiosity on
my current machine.

Speaking of radiosity, the default finishes for objects are diffuse 0.65,
ambient 0.1 or 0.0.  Is there any way to alter the default finish?
Ambient_light in global_settings is inappropriate as I want a good sky for
radiosity purposes.

Any ideas?
-- 
David Wallace
TenArbor Consulting
"Just In Time Cash"
www.tenarbor.com


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From: Warp
Subject: Re: Memory access limits
Date: 12 May 2004 08:01:47
Message: <40a2122b@news.povray.org>
David Wallace <dar### [at] earthlinknet> wrote:
> Is there any way to alter the default finish?

  Actually there is:

#default { finish { diffuse 0.5 } }

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -


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