POV-Ray : Newsgroups : povray.general : POV and hyperthreading Server Time
4 Aug 2024 06:18:42 EDT (-0400)
  POV and hyperthreading (Message 4 to 13 of 13)  
<<< Previous 3 Messages Goto Initial 10 Messages
From: Anto Matkovic
Subject: Re: POV and hyperthreading
Date: 10 Aug 2003 13:42:32
Message: <3f368408@news.povray.org>
"Ken" <tyl### [at] pacbellnet> wrote in message
news:3F35319F.F6FA6A73@pacbell.net...
> See also -
> http://www.it-berater.org/smpov.htm
>
Thanks, I just figured how it works - works very well. Theo Gottwald did a
god job.

Anto


Post a reply to this message

From: ABX
Subject: Re: POV and hyperthreading
Date: 11 Aug 2003 05:12:41
Message: <ncnejvcpnh6fi0pvhr1bl2m5l6av0jdi81@4ax.com>
On Sat, 9 Aug 2003 18:39:29 +0200, "Anto Matkovic" <ant### [at] matkoviccom> wrote:
> Is there a POV-Ray patch or something for hyperthreading?

See: http://news.povray.org/povray.windows/26402/

ABX


Post a reply to this message

From: Theo Gottwald *
Subject: Re: POV and hyperthreading
Date: 12 Aug 2003 09:31:40
Message: <3f38ec3c$1@news.povray.org>
Thanks, Anto!

Since the new explanation "smpov How to" is advertised at povray.org I had
(alltogether) ... 1097 Downloads from SMPOV.
Even people tell me actually where the limits of the current implementation
are.
Mostly if they use tools like Poser, poseray, moray when there are "absolut
pathes in the include-files.
i dont have these tools currently so I could not test that till now.

So far I already have some ideas for a next version. Now I'll take a look if
someone has been
posting numbers if it makes sense to use SMPOV with hyperthreading.

--Theo
-----------------------------------------------------------------------
Distributed Network-Rendering or Local SMP-Rendering. With SMPOV and
POV-Ray 3.5. * Download free at: http://www.it-berater.org/smpov.htm


"Anto Matkovic" <ant### [at] matkoviccom> schrieb im Newsbeitrag
news:3f368408@news.povray.org...
>
> "Ken" <tyl### [at] pacbellnet> wrote in message
> news:3F35319F.F6FA6A73@pacbell.net...
> > See also -
> > http://www.it-berater.org/smpov.htm
> >
> Thanks, I just figured how it works - works very well. Theo Gottwald did a
> god job.
>
> Anto
>
>


Post a reply to this message

From: Anto Matkovic
Subject: Re: POV and hyperthreading
Date: 14 Aug 2003 11:34:51
Message: <3f3bac1b@news.povray.org>
"Theo Gottwald *" <The### [at] t-onlinede> wrote in message
news:3f38ec3c$1@news.povray.org...

> So far I already have some ideas for a next version. Now I'll take a look
if
> someone has been
> posting numbers if it makes sense to use SMPOV with hyperthreading.
>
Well, seems it haven't sense, even both of procs are on 100%.
Skyvase on 1024x768 AA 0.1:
skyvase.pov rendered in 1024x768 in 2 Tiles (H) from 08-14-2003 / 17:12:36
to 08-14-2003 / 17:13:14 (38).

Maybe I doing something wrong.

This is near the same as rendering with two POV's with two separate ini
files, every one with output to a different half-image file.
(17 and 22 seconds).
Single instance of POV need 29s for all.

However, good surprise for me is possibility to render radiosity (with some
my own files) in parts. I remebering many problems with
POV-Ray 3.0 in this case. Well, this is adavantage of POV 3.5...

Anto


Post a reply to this message

From: ABX
Subject: Re: POV and hyperthreading
Date: 14 Aug 2003 11:41:44
Message: <m5bnjvk76vlrsr9akdr3f7ebbu3lq69l67@4ax.com>
On Thu, 14 Aug 2003 17:34:35 +0200, "Anto Matkovic" <ant### [at] matkoviccom> wrote:
> However, good surprise for me is possibility to render radiosity (with some
> my own files) in parts. I remebering many problems with
> POV-Ray 3.0 in this case. Well, this is adavantage of POV 3.5...

AFAIK problem with radiosity rendered in parts in 3.5 is the same like in POV
before 3.5. I would rather say that thanks to better processors we can use
better radiosity settings so artefacts are less visible. Can be this your
case?

ABX


Post a reply to this message

From: Anto Matkovic
Subject: Re: POV and hyperthreading
Date: 14 Aug 2003 16:39:36
Message: <3f3bf388@news.povray.org>
> AFAIK problem with radiosity rendered in parts in 3.5 is the same like in
POV
> before 3.5. I would rather say that thanks to better processors we can use
> better radiosity settings so artefacts are less visible. Can be this your
> case?
>
This was with some entries for IRTC with POV 3.0 (1997, 98..). I stopped
render with
radiosity, closed
POV, and tried to continue render. New rendering part was a bit lighter or
darker than old part. No problem to fix this in bitmap
program, bur IRTC rule was: you can only convert image or  ajust gamma or
brightness-contrast. So, Pentium 2 from these days had to work continiously
for days or
weeks.

Similar problem can be with some commercial raytracers, if they calculate
radiance map per bucket. You can see different radiosity from quad to quad
of the render view.

As I can see,  POV-Ray 35 haven't this problem, because of writting '.rca'
files to HDD (I suppose this is a radiance map file, can't find anything
about in
docs for now), so it possible to rerun radiosity render.

How this work with simultaneuosly rendered parts, I don't know  for now.

Anto


Post a reply to this message

From: Theo Gottwald *
Subject: Re: POV and hyperthreading
Date: 23 Aug 2003 06:03:47
Message: <3f473c03$1@news.povray.org>
Hi Anto,

Here are my numbers:

skyvase.pov rendered in 1024x768 in 1 Tiles (-) from 08-23-2003 / 11:53:28
to 08-23-2003 / 11:54:15 (47).

skyvase.pov rendered in 1024x768 in 2 Tiles (H) from 08-23-2003 / 11:54:22
to 08-23-2003 / 11:54:58 (36).

skyvase.pov rendered in 1024x768 in 2 Tiles (V) from 08-23-2003 / 11:55:04
to 08-23-2003 / 11:55:52 (48).

skyvase.pov rendered in 1024x768 in 4 Tiles (H) from 08-23-2003 / 11:56:10
to 08-23-2003 / 11:57:02 (52).

However - all rendered locally with my 2 CPU's. You see the Overhead when I
make 4 tiles makes it even slower then when I render this in 1 tile.

In one sentece: Scenes which need only very short rendering (30 Seconds) may
not be the best candidates for SMPOV and Hyperthreading. I have counted that
even before the second instance starts up, 4 Seconds are gone.

Your numbers:
38 Second - 29 Seconds = 9 Seconds diffrence. How long does it take for your
POV-Ray to load?

Remeber we load two instances of POV-Ray. Secondly they start up and load
the POV-File.

Did you include the "loading time" while measuring the 29 Seconds?
Maybe in that case POV-Ray was already loaded and shurely even the file.


Secondly Pictures which need more time to pre-process then actual render
time
maybe not the best candidates for "Tiling" in Hyperthreading Systems. (=
rendering them in pieces).
(General statement)
The point is that we start 2 instances of POV-Ray and EACH does the full
Preprocessing.

If you would have a time win of 20% for using the Hyperthreading, you have a
loose
for doing the Pre-Processing two times. I have no idea if "preprocessing"
can be "hyperthreaded" or not.
On my Dual-Athlon i've found that Preprocessing produces nearly no CPU-usage
(I used PartixGen - very intresting and fully distributable) - so I would
say give it a try.

With real SMP-Systems (my Athlon here) the situation is diffrent.

2. SMPOV and the Renderagent need also some calculation- and reaction time.
   They are primarily made for pictures which need long time to render so
   the "builtin reaction-times" are rather slow to save CPU-time.
  Reaction time is, between SMPOV giving the Orders for Rendering out till
the RenderAgents react.
  Secondly till they notice that POV-Ray is ready. Then thirdly SMPOV has to
get a message that all
  the tiles are ready. And fourth it has to start PicPender.exe to "put al
lthe tiles together".
  There are several reaction times that may add up to 5 Seconds. Add your
loading times and some
  time for "Preprocessing"

3. Two instances of POV-Ray are started. (=Loading time for POV-Ray).

4. To find out where the times are, you can render it with SMPOV, make the
"Tiling" on 1
   (so there will be only 1 instance started). Then make a second try (tling
on 2) - try "H" and "V"
   there are diffrences. Then you have numbers in the log-file. These
numbers include some overhead,
   but at least you are shure the settings are really the same for all runs.

Keep me informed if you make a second try.

--Theo
-----------------------------------------------------------------------
Distributed Network-Rendering or Local SMP-Rendering. With SMPOV and
POV-Ray 3.5. * Download free at: http://www.it-berater.org/smpov.htm


Post a reply to this message

From: Anto Matkovic
Subject: Re: POV and hyperthreading
Date: 30 Aug 2003 23:47:24
Message: <3f516fcc@news.povray.org>
Hi Theo,
sorry for delay. I decided to spent my vacation on the sea instead rendering
the IRTC entry :).

> In one sentece: Scenes which need only very short rendering (30 Seconds)
may
> not be the best candidates for SMPOV and Hyperthreading.

I can confirm that. Here are numbers  for 'optics.pov' at 1024x768 AA 0.1:
Prozessoren:  2
CPU 1 Speed:  3354 Mhz.
CPU 2 Speed:  3354 Mhz. ( I dont know why, because all other in machine
recognizes original 3006 Mhz)

optics.pov rendered in 1024x768 in 2 Tiles (V) from 08-30-2003 / 22:44:59 to
08-30-2003 / 23:32:53 (2875).

Single instance od POV need 3321 seconds. POV and scene already loaded.

> Your numbers:
> 38 Second - 29 Seconds = 9 Seconds diffrence. How long does it take for
your
> POV-Ray to load?
about few seconds...

> Did you include the "loading time" while measuring the 29 Seconds?
No.

> Maybe in that case POV-Ray was already loaded and shurely even the file.
Yes.
>

Anto


Post a reply to this message

From: Theo Gottwald *
Subject: Re: POV and hyperthreading
Date: 1 Sep 2003 06:09:34
Message: <3f531ade$1@news.povray.org>
Hi Anto,


I hope your holiday was ok!

Your numbers show that under equal circumstances:

> optics.pov rendered in 1024x768 in 2 Tiles (V) from 08-30-2003 / 22:44:59
to
> 08-30-2003 / 23:32:53 (2875).
>
> Single instance od POV need 3321 seconds. POV and scene already loaded.

You get a small timewin of around 24% including the loading times etc..
Thats what you can get using hyperthreading.
As we know now, its not so intresting for pictures which render only few
seconds.


--Theo
-----------------------------------------------------------------------
Distributed Network-Rendering or Local SMP-Rendering. With SMPOV and
POV-Ray 3.5. * Download free at: http://www.it-berater.org/smpov.htm




"Anto Matkovic" <ant### [at] matkoviccom> schrieb im Newsbeitrag
news:3f516fcc@news.povray.org...
> Hi Theo,
> sorry for delay. I decided to spent my vacation on the sea instead
rendering
> the IRTC entry :).
>
> > In one sentece: Scenes which need only very short rendering (30 Seconds)
> may
> > not be the best candidates for SMPOV and Hyperthreading.
>
> I can confirm that. Here are numbers  for 'optics.pov' at 1024x768 AA 0.1:
> Prozessoren:  2
> CPU 1 Speed:  3354 Mhz.
> CPU 2 Speed:  3354 Mhz. ( I dont know why, because all other in machine
> recognizes original 3006 Mhz)
>
> optics.pov rendered in 1024x768 in 2 Tiles (V) from 08-30-2003 / 22:44:59
to
> 08-30-2003 / 23:32:53 (2875).
>
> Single instance od POV need 3321 seconds. POV and scene already loaded.
>
> > Your numbers:
> > 38 Second - 29 Seconds = 9 Seconds diffrence. How long does it take for
> your
> > POV-Ray to load?
> about few seconds...
>
> > Did you include the "loading time" while measuring the 29 Seconds?
> No.
>
> > Maybe in that case POV-Ray was already loaded and shurely even the file.
> Yes.
> >
>
> Anto
>
>
>
>


Post a reply to this message

From: iceqb
Subject: Re: POV and hyperthreading
Date: 29 Jun 2005 13:35:00
Message: <web.42c2dac57debdd14a41dbe760@news.povray.org>
"Theo Gottwald *" <The### [at] t-onlinede> wrote:
> Hi Anto,
>
> Here are my numbers:
>
> skyvase.pov rendered in 1024x768 in 1 Tiles (-) from 08-23-2003 / 11:53:28
> to 08-23-2003 / 11:54:15 (47).
>
> skyvase.pov rendered in 1024x768 in 2 Tiles (H) from 08-23-2003 / 11:54:22
> to 08-23-2003 / 11:54:58 (36).
>
> skyvase.pov rendered in 1024x768 in 2 Tiles (V) from 08-23-2003 / 11:55:04
> to 08-23-2003 / 11:55:52 (48).
>
> skyvase.pov rendered in 1024x768 in 4 Tiles (H) from 08-23-2003 / 11:56:10
> to 08-23-2003 / 11:57:02 (52).
>
> However - all rendered locally with my 2 CPU's. You see the Overhead when I
> make 4 tiles makes it even slower then when I render this in 1 tile.
>
> In one sentece: Scenes which need only very short rendering (30 Seconds) may
> not be the best candidates for SMPOV and Hyperthreading. I have counted that
> even before the second instance starts up, 4 Seconds are gone.
>
> Your numbers:
> 38 Second - 29 Seconds = 9 Seconds diffrence. How long does it take for your
> POV-Ray to load?
>
> Remeber we load two instances of POV-Ray. Secondly they start up and load
> the POV-File.
>
> Did you include the "loading time" while measuring the 29 Seconds?
> Maybe in that case POV-Ray was already loaded and shurely even the file.
>
>
> Secondly Pictures which need more time to pre-process then actual render
> time
> maybe not the best candidates for "Tiling" in Hyperthreading Systems. (=
> rendering them in pieces).
> (General statement)
> The point is that we start 2 instances of POV-Ray and EACH does the full
> Preprocessing.
>
> If you would have a time win of 20% for using the Hyperthreading, you have a
> loose
> for doing the Pre-Processing two times. I have no idea if "preprocessing"
> can be "hyperthreaded" or not.
> On my Dual-Athlon i've found that Preprocessing produces nearly no CPU-usage
> (I used PartixGen - very intresting and fully distributable) - so I would
> say give it a try.
>
> With real SMP-Systems (my Athlon here) the situation is diffrent.
>
> 2. SMPOV and the Renderagent need also some calculation- and reaction time.
>    They are primarily made for pictures which need long time to render so
>    the "builtin reaction-times" are rather slow to save CPU-time.
>   Reaction time is, between SMPOV giving the Orders for Rendering out till
> the RenderAgents react.
>   Secondly till they notice that POV-Ray is ready. Then thirdly SMPOV has to
> get a message that all
>   the tiles are ready. And fourth it has to start PicPender.exe to "put al
> lthe tiles together".
>   There are several reaction times that may add up to 5 Seconds. Add your
> loading times and some
>   time for "Preprocessing"
>
> 3. Two instances of POV-Ray are started. (=Loading time for POV-Ray).
>
> 4. To find out where the times are, you can render it with SMPOV, make the
> "Tiling" on 1
>    (so there will be only 1 instance started). Then make a second try (tling
> on 2) - try "H" and "V"
>    there are diffrences. Then you have numbers in the log-file. These
> numbers include some overhead,
>    but at least you are shure the settings are really the same for all runs.
>
> Keep me informed if you make a second try.
>
> --Theo
> -----------------------------------------------------------------------
> Distributed Network-Rendering or Local SMP-Rendering. With SMPOV and
> POV-Ray 3.5. * Download free at: http://www.it-berater.org/smpov.htm


I tried that, but I can't seem to get SMPov to run good on my P4 with HT, he
still only renders on one of the two virtual CPU's.


Post a reply to this message

<<< Previous 3 Messages Goto Initial 10 Messages

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.