I know, this might have been asked quite often. But is there a listing
of POV versions running on multiprocessor platfoms?
I'm especially thinking of a dual celeron solution.
What OS do I need (NT,Linux,...)?
Any suggestions. Anyone already made experiences with this matter?

Karl

Post a reply to this message

Karl Pelzer wrote:
> 
> I know, this might have been asked quite often. But is there a listing
> of POV versions running on multiprocessor platfoms?
> I'm especially thinking of a dual celeron solution.
> What OS do I need (NT,Linux,...)?
> Any suggestions. Anyone already made experiences with this matter?
> 
> Karl

You can find some information about running POV-Ray on multiple processors
here -

http://www.students.tut.fi/~warp/povVFAQ/languageVFAQ.html#multiprocessor

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken wrote:
> 
> You can find some information about running POV-Ray on multiple processors
> here -
> 
> http://www.students.tut.fi/~warp/povVFAQ/languageVFAQ.html#multiprocessor
> 
> --
> Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Thanks Ken.

Again you saved me. This article is mostly about NT. It seems to be easy
to let two copies of POV render the same time (O.K. some restrictions).
But this might be useful for animations. One copy renders the even
frames and the other copy of POV renders the odd frames.

Anyone here made experiences with linux or with a multithreaded version
of POV?

Karl

Post a reply to this message

On Tue, 29 Feb 2000 08:19:31 +0100, Karl Pelzer
<Kar### [at] t-onlinede> wrote:

>I know, this might have been asked quite often. But is there a listing
>of POV versions running on multiprocessor platfoms?
>I'm especially thinking of a dual celeron solution.
>What OS do I need (NT,Linux,...)?
>Any suggestions. Anyone already made experiences with this matter?
>
>Karl

Being the lazy bum that I am, I'll just copy & paste from a reply I
send to the exact same question a couple of days ago. Here we go...

POV-Ray is indeed currently incapable of making use of SMPs. 
There have been PVM ports of POV-Ray but I don't think a 3.1 one 
is available let alone MegaPOV.

But, there is always a workaround :) If you can't take advantage of 
multithreading, do so with multitasking. Run two instances of POV 
and give each of them a separate portion of the image. Depending 
on the image, one part may take significantly longer to render than 
the other, imposing some difficulties. There are three basic ways to 
split up the work:

1. Give the top half of the image to one instance of POV and the 
bottom half -- to the other one.

2. The same, but use left/right halves instead.

3. Make one instance render the odd lines and the other instance -- 
the even lines. To do so, type this in the command line (the INI file 
won't work because both files share a single povray.ini):

+uf +kfi0 +kff1 +ef0

and this in the command line of the second instance of POV:

+uf +kfi0 +kff1 +sf1

This will make two images, say output0.tga and output1.tga . The 
first one will contain the even lines and the second one will contain 
the odd lines. Open the images in a paint program and deinterlace 
them.

I hope this works OK for you.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

Peter Popov wrote:
<large snip>

> 
> I hope this works OK for you.
> 

<snip>

Thanks.
But honestly I'm not satisfied yet. Your solution goes into the same
direction as the ideas found with Ken's link.
Thanks again though!

Karl

Post a reply to this message

On Wed, 01 Mar 2000 22:09:46 +0100, Karl Pelzer wrote:

>But honestly I'm not satisfied yet. 

THERE IS NO MULTITHREADED VERSION OF POV-RAY.  PERIOD.  

If you really must know why, go read one of the dozens of threads over in
povray.programming, or even in this very group, that cover that topic in
excruciating detail.  The short version, though, is that coding properly
for multiple threads isn't as easy as Microsoft wants you to believe it is.

Besides, process switches are nearly as fast as thread switches, so what's
the problem with the solutions presented so far?

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

On 1 Mar 2000 16:49:28 -0500, ron### [at] povrayorg (Ron Parker)
wrote:

>On Wed, 01 Mar 2000 22:09:46 +0100, Karl Pelzer wrote:
>
>>But honestly I'm not satisfied yet. 
>
>THERE IS NO MULTITHREADED VERSION OF POV-RAY.  PERIOD.  

Gee, these keyboards are getting crappier every day. Ron's caps lock
key got stuck, and the darn thing isn't even three months old. 

>If you really must know why, go read one of the dozens of threads over in
>povray.programming, or even in this very group, that cover that topic in
>excruciating detail.  The short version, though, is that coding properly
>for multiple threads isn't as easy as Microsoft wants you to believe it is.

I believe the problem lies in basically having to redesign everything
from scratch, which the Team would not be likely to do solely for the
sake of multi-threadedness.

>Besides, process switches are nearly as fast as thread switches, so what's
>the problem with the solutions presented so far?

Memory consumption? I believe two threads can share the same memory
(for reading at least) but not so for two processes.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

On Thu, 02 Mar 2000 00:40:47 +0200, Peter Popov wrote:
>Gee, these keyboards are getting crappier every day. Ron's caps lock
>key got stuck, and the darn thing isn't even three months old. 

Actually, that keyboard is more like two years old.  But believe it
or not, I didn't use caps lock to type that line. 

>I believe the problem lies in basically having to redesign everything
>from scratch, which the Team would not be likely to do solely for the
>sake of multi-threadedness.

Pretty much.  Mainly, the problem lies in the overuse of global variables.
Since that's such a bad idea anyway, we're working on getting them under
control for "a future release" but it still might not be easy to do 
multiple threads, due to the fact that there is no standardized way to
do multiple threads across all supported operating systems.

>Memory consumption? I believe two threads can share the same memory
>(for reading at least) but not so for two processes.

Two threads in the same process share all the same memory; this is
the main problem: they can trample on each other's global variables.
Having variables local to a specific thread is actually somewhat
complicated, at least in Windows.

Two processes should be able to share an executable image, but I 
wouldn't be the least bit surprised to hear that this isn't implemented
on Windows-based operating systems, or at least those before W2K.  I 
know I was surprised to find out there's essentially no memory 
protection on executable code (though I went through the motions and
VirtualProtect'd the pages I needed to modify anyway, just for the
sake of safety.  They may one day actually make that code do something.)

Two processes can opt to share a read/write region of memory, at least
in Windows, by using memory-mapped files, but this is fraught with 
danger in that some versions of Windows will map them to the same 
address in different processes (9x, Millennium) and some will map 
them to completely different addresses (NT 4 and 2000).  This is a 
problem if you elect to store any pointers in the shared memory, as
they'd only be valid in one process.  The workaround is relatively 
simple, but it's still a pain to have to think about such things.
Worse, if you do your development on 9x, you'd never know the problem
existed.  Even Microsoft has fallen prey to this caveat in one of 
their more specialized development tools.  (Though to be fair, the
tool was for working with a feature that didn't exist on NT in a 
publicly released version at the time.  Unfortunately, I was using 
an unreleased (i.e. not even beta) version, and I needed the tools.)

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

On a dual processor NT machine (NT v4) you can run 2 copies of POVRay at the
same time with minimal interference.  To minimize CPU thrashing I'd suggest
you use the set affinity command via the task manager processes tab.

--
Jim

Check out my web site  http://www.kressworks.com/

Ron Parker <ron### [at] povrayorg> wrote in message
news:slr### [at] parkerrfwicom...
> On Thu, 02 Mar 2000 00:40:47 +0200, Peter Popov wrote:
> >Gee, these keyboards are getting crappier every day. Ron's caps lock
> >key got stuck, and the darn thing isn't even three months old.
>
> Actually, that keyboard is more like two years old.  But believe it
> or not, I didn't use caps lock to type that line.
>
> >I believe the problem lies in basically having to redesign everything
> >from scratch, which the Team would not be likely to do solely for the
> >sake of multi-threadedness.
>
> Pretty much.  Mainly, the problem lies in the overuse of global variables.
> Since that's such a bad idea anyway, we're working on getting them under
> control for "a future release" but it still might not be easy to do
> multiple threads, due to the fact that there is no standardized way to
> do multiple threads across all supported operating systems.
>
> >Memory consumption? I believe two threads can share the same memory
> >(for reading at least) but not so for two processes.
>
> Two threads in the same process share all the same memory; this is
> the main problem: they can trample on each other's global variables.
> Having variables local to a specific thread is actually somewhat
> complicated, at least in Windows.
>
> Two processes should be able to share an executable image, but I
> wouldn't be the least bit surprised to hear that this isn't implemented
> on Windows-based operating systems, or at least those before W2K.  I
> know I was surprised to find out there's essentially no memory
> protection on executable code (though I went through the motions and
> VirtualProtect'd the pages I needed to modify anyway, just for the
> sake of safety.  They may one day actually make that code do something.)
>
> Two processes can opt to share a read/write region of memory, at least
> in Windows, by using memory-mapped files, but this is fraught with
> danger in that some versions of Windows will map them to the same
> address in different processes (9x, Millennium) and some will map
> them to completely different addresses (NT 4 and 2000).  This is a
> problem if you elect to store any pointers in the shared memory, as
> they'd only be valid in one process.  The workaround is relatively
> simple, but it's still a pain to have to think about such things.
> Worse, if you do your development on 9x, you'd never know the problem
> existed.  Even Microsoft has fallen prey to this caveat in one of
> their more specialized development tools.  (Though to be fair, the
> tool was for working with a feature that didn't exist on NT in a
> publicly released version at the time.  Unfortunately, I was using
> an unreleased (i.e. not even beta) version, and I needed the tools.)
>
> --
> These are my opinions.  I do NOT speak for the POV-Team.
> The superpatch: http://www2.fwi.com/~parkerr/superpatch/
> My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

Ron Parker wrote:
> 
> On Thu, 02 Mar 2000 00:40:47 +0200, Peter Popov wrote:
> >Gee, these keyboards are getting crappier every day. Ron's caps lock
> >key got stuck, and the darn thing isn't even three months old.
> 
> Actually, that keyboard is more like two years old.  But believe it
> or not, I didn't use caps lock to type that line.

My keyboard is 16 years old and works as well today as when I first
purchased it. About once every 2 years I pop all the keys off and
throw them into the dishwaser but other than that it has seen no
other maintenance.

True story - date code on my keyboard is 1984 (the year the world
was really supposed to end)

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

"Ken" <tyl### [at] pacbellnet> wrote :
>
> 1984 (the year the world
> was really supposed to end)
>

    Ehh? Did I miss something?

Post a reply to this message

Bill DeWitt wrote:
> 
> "Ken" <tyl### [at] pacbellnet> wrote :
> >
> > 1984 (the year the world
> > was really supposed to end)
> >
> 
>     Ehh? Did I miss something?

George Orwell's book  "1984". Required reading in my English Lit. class
in high school.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

"Ken" <tyl### [at] pacbellnet> wrote :
> >
> >     Ehh? Did I miss something?
>
> George Orwell's book  "1984". Required reading in my English Lit. class
> in high school.
>

    One of my favorites, but I don't remember anything about the world
ending in it...?

Post a reply to this message

The main character gave in to "the system" and might as
well have been dead, for all the free thought he had. i.e. he
had none. He seems to have been the last character to dare
do anything that "Big Brother" didn't like. He just became
a mindless cog in a vast machine. This sounds too much like
the end of the world to anyone who likes to be different.

Bill DeWitt wrote:
> 
> "Ken" <tyl### [at] pacbellnet> wrote :
> > >
> > >     Ehh? Did I miss something?
> >
> > George Orwell's book  "1984". Required reading in my English Lit. class
> > in high school.
> >
> 
>     One of my favorites, but I don't remember anything about the world
> ending in it...?

-- 
Mr. Art

"Often the appearance of reality is more important 
than the reality of the appearance."
Bill DeWitt 2000

Post a reply to this message

Ken wrote:
> 
> My keyboard is 16 years old and works as well today as when I first
> purchased it. About once every 2 years I pop all the keys off and
> throw them into the dishwaser but other than that it has seen no
> other maintenance.

Too much work. Take a dish large enough to hold the keyboard.
Fill it with Screen cleaning foam. Dip the keyboard in it for
about two hours and take it out -> clean.

Markus

Post a reply to this message

Markus Becker wrote:
> 
> Ken wrote:
> >
> > My keyboard is 16 years old and works as well today as when I first
> > purchased it. About once every 2 years I pop all the keys off and
> > throw them into the dishwaser but other than that it has seen no
> > other maintenance.
> 
> Too much work. Take a dish large enough to hold the keyboard.
> Fill it with Screen cleaning foam. Dip the keyboard in it for
> about two hours and take it out -> clean.
> 
> Markus

Your method has merits but with my method I also take the time to blow
out the dust bunnies, dead skin cells, and the stray hair of two that
accumulate underneath the keys and occasionaly cause erratic behavior.

I will add that my keyboard was manufactured in Germany and I have to
say that the German reputation for solid engineering is evident in
this product.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

I have had keyboards that didn't last two years.
Mostly because the letters wore off.

Ken wrote:
> 
> Ron Parker wrote:
> >
> > On Thu, 02 Mar 2000 00:40:47 +0200, Peter Popov wrote:
> > >Gee, these keyboards are getting crappier every day. Ron's caps lock
> > >key got stuck, and the darn thing isn't even three months old.
> >
> > Actually, that keyboard is more like two years old.  But believe it
> > or not, I didn't use caps lock to type that line.
> 
> My keyboard is 16 years old and works as well today as when I first
> purchased it. About once every 2 years I pop all the keys off and
> throw them into the dishwaser but other than that it has seen no
> other maintenance.
> 
> True story - date code on my keyboard is 1984 (the year the world
> was really supposed to end)
> 
> --
> Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

-- 
Mr. Art

"Often the appearance of reality is more important 
than the reality of the appearance."
Bill DeWitt 2000

Post a reply to this message

Markus Becker wrote:
> Too much work. Take a dish large enough to hold the keyboard.
> Fill it with Screen cleaning foam. Dip the keyboard in it for
> about two hours and take it out -> clean.
> 
> Markus

I had a keyboard with coffee spilled in it once.
Washed it in water and detergent, rinsed with distilled water and it
worked fine.

PoD.

Post a reply to this message

Ken <tyl### [at] pacbellnet> wrote:
: True story - date code on my keyboard is 1984

  What!?! You are not using a Win95-keyboard? Shame on you!

  (My keyboard is about 6 years old)

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

On 2 Mar 2000 10:54:30 -0500, Nieminen Juha wrote:
>Ken <tyl### [at] pacbellnet> wrote:
>: True story - date code on my keyboard is 1984
>
>  What!?! You are not using a Win95-keyboard? Shame on you!
>
>  (My keyboard is about 6 years old)

My keyboards at home are neither win95-keyboards.  One is at
least six years old, and the other I don't know as I picked it
up for $6 at Goodwill.  Praps I'll look up the date codes next
time I think about it.

-- 
These are my opinions.  I do NOT speak for the POV-Team.
The superpatch: http://www2.fwi.com/~parkerr/superpatch/
My other stuff: http://www2.fwi.com/~parkerr/traces.html

Post a reply to this message

"mr.art" <mr.### [at] gcinet> wrote :
>
> This sounds too much like
> the end of the world to anyone who likes to be different.
>

    Ah, not the end of the world, just the end of a particular world that
you prefer. Not to worry, happens to me every day.

Post a reply to this message

Nieminen Juha <war### [at] sarakerttunencstutfi> writes:

> Ken <tyl### [at] pacbellnet> wrote:
> : True story - date code on my keyboard is 1984
> 
>   What!?! You are not using a Win95-keyboard? Shame on you!
> 
>   (My keyboard is about 6 years old)

:-)

My keyboard is 8 years old and I will keep it until they 
invent a keyboard with a larger space bar (i.e. without
these silly Windows-keys).

Thomas

-- 
http://thomas.willhalm.de/ (includes pgp key)

Post a reply to this message

Ron Parker wrote:
> 
> On Wed, 01 Mar 2000 22:09:46 +0100, Karl Pelzer wrote:
> 
> >But honestly I'm not satisfied yet.
> 
> THERE IS NO MULTITHREADED VERSION OF POV-RAY.  PERIOD.
> 
> If you really must know why, go read one of the dozens of threads over in
> povray.programming, or even in this very group, that cover that topic in
> excruciating detail. 

O.K. I'll shut up now...

Karl

Post a reply to this message

On 1 Mar 2000 23:06:23 -0500, ron### [at] povrayorg (Ron Parker)
wrote:

>On Thu, 02 Mar 2000 00:40:47 +0200, Peter Popov wrote:
>>Gee, these keyboards are getting crappier every day. Ron's caps lock
>>key got stuck, and the darn thing isn't even three months old. 
>
>Actually, that keyboard is more like two years old.  But believe it
>or not, I didn't use caps lock to type that line. 

I trust you :) I am yet to see a programmer use the caps lock key for
something shorter than 255 characters. The use of the shift key makes
typing constant names with underscores in them really easy.

And I wasn't serious about the keyboard either.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

Ken wrote:
> 
> Your method has merits but with my method I also take the time to blow
> out the dust bunnies, dead skin cells, and the stray hair of two that
> accumulate underneath the keys and occasionaly cause erratic behavior.

That's right. But from time to time I simply turn it upside down
to take out ashes, tobacco and whatnot ;-)

Markus, made in Germany

Post a reply to this message

"mr.art" wrote:
> 
> I have had keyboards that didn't last two years.
> Mostly because the letters wore off.

Why do you need letters?

-Mark Gordon

Post a reply to this message

Bad typing skills. And stop sounding like my wife.:)

Mark Gordon wrote:
> 
> "mr.art" wrote:
> >
> > I have had keyboards that didn't last two years.
> > Mostly because the letters wore off.
> 
> Why do you need letters?
> 
> -Mark Gordon

-- 
Mr. Art

"Often the appearance of reality is more important 
than the reality of the appearance."
Bill DeWitt 2000

Post a reply to this message

On Wed, 08 Mar 2000 18:42:53 -0900 "mr.art" <mr.### [at] gcinet> wrote:

>Bad typing skills. And stop sounding like my wife.:)

  Hi, Mr. Art. Don't buy another keyboard just because the letter wore
off - get a permanent fine point marker like the Sharpee brand and put
'em back on the keys.

  I've wore down the little 'nubs' used for touch typing on the 'F' and
'J' keys but a tiny dab of epoxy or maybe even silicone sealant (not
silicone bathtub caulk - it doesn't dry out enough) is enough to regain
the feel of the keyboard position.

  Ever try Mavis Beacon's typing programs? I used to have it on my old
system and it can be fun at times. I think there was one exercise that
measured typing speed in terms of a car speedometer. That was my
favorite.

-- 
Alan - ako### [at] povrayorg - a k o n g <at> p o v r a y <dot> o r g
http://www.povray.org - Home of the Persistence of Vision Ray Tracer

Post a reply to this message

I have tried to use Mavis Beacon's typing programs. And they have
helped.
But having large fingers and arthritis and mild carpeltunnel (sp?) 
and more whining and more whining ...
Needless to say, I don't type very fast. So I never could get to the
speeds that could be bragged about. The only thing that I can do to help
is use a Dvorak keyboard. Keeps me from having to move the fingers as
much.

p.s. Take your time reading this as it took me some time to type it.:)

Alan Kong wrote:
> 
> On Wed, 08 Mar 2000 18:42:53 -0900 "mr.art" <mr.### [at] gcinet> wrote:
> 
> >Bad typing skills. And stop sounding like my wife.:)
> 
>   Hi, Mr. Art. Don't buy another keyboard just because the letter wore
> off - get a permanent fine point marker like the Sharpee brand and put
> 'em back on the keys.
> 
>   I've wore down the little 'nubs' used for touch typing on the 'F' and
> 'J' keys but a tiny dab of epoxy or maybe even silicone sealant (not
> silicone bathtub caulk - it doesn't dry out enough) is enough to regain
> the feel of the keyboard position.
> 
>   Ever try Mavis Beacon's typing programs? I used to have it on my old
> system and it can be fun at times. I think there was one exercise that
> measured typing speed in terms of a car speedometer. That was my
> favorite.
> 
> --
> Alan - ako### [at] povrayorg - a k o n g <at> p o v r a y <dot> o r g
> http://www.povray.org - Home of the Persistence of Vision Ray Tracer

-- 
Mr. Art

"Often the appearance of reality is more important 
than the reality of the appearance."
Bill DeWitt 2000

Post a reply to this message

On Thu, 09 Mar 2000 18:21:01 -0900 "mr.art" <mr.### [at] gcinet> wrote:

>...But having large fingers and arthritis and mild carpeltunnel (sp?) 
>and...

  Okay, I understand the situation better now. More practice may make
matters worse :(

-- 
Alan - ako### [at] povrayorg - a k o n g <at> p o v r a y <dot> o r g
http://www.povray.org - Home of the Persistence of Vision Ray Tracer

Post a reply to this message