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  Mac newbie ... (Message 1 to 8 of 8)  
From: Adin
Subject: Mac newbie ...
Date: 20 May 2002 04:44:42
Message: <3ce8b77a$1@news.povray.org>
Ok guys ... maybe you can help me.

I own a PowerMac G4 800 dp with 1.2 gig ram installed.

I benchmarked my mac with POV-Ray Using the www.tabsnet.com method. And in
fact my mac is slower then my PC (AMD Athlon 1200 mhz, 512 mb ram).

Shouldn't the mac be faster in any case ? Does anyone have any ideas how to
speed up POV-Ray ?

I know i may be pretty much an idiot in this case, nut i don't know much
about X yet.

Thanks for any help in advance.


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From: Thorsten Froehlich
Subject: Re: Mac newbie ...
Date: 20 May 2002 09:50:07
Message: <3ce8ff0f@news.povray.org>
In article <3ce8b77a$1@news.povray.org> , "Adin" <azu### [at] hotmailcom>
wrote:

> Ok guys ... maybe you can help me.
>
> I own a PowerMac G4 800 dp with 1.2 gig ram installed.
>
> I benchmarked my mac with POV-Ray Using the www.tabsnet.com method. And in
> fact my mac is slower then my PC (AMD Athlon 1200 mhz, 512 mb ram).
>
> Shouldn't the mac be faster in any case ? Does anyone have any ideas how to
> speed up POV-Ray ?
>
> I know i may be pretty much an idiot in this case, nut i don't know much
> about X yet.

A few points to help you:

A) Don't run any benchmarks under Mac OS X Classic.  Use Mac OS 8/9 with
virtual memory and file sharing *off*.

B) You cannot reproduce the exact settings used in the www.tabsnet.com
benchmark with the Mac Render Settings dialog (see below).

C) You probably forgot to set the highest priority in the Preferences dialog.
The settings suggested under <http://www.tabsnet.com/micons/settings2.gif> are
wrong, unfortunately :-(

D) POV-Ray is not PhotoShop, so what do you expect?  See the notes on
<http://mac.povray.org/support/faq.html#what_aboutg4>

E) The benchmark you used has been unsuitable for the last few years as it
only takes a few seconds, which is not enough to make an adequate measurement.
This is also noted on the site you mentioned (somewhere).

F) At least half of the benchmark results listed on the site have no validity
as they are of a random nature due to most people making mistakes setting up
their systems.  If you look carefully you will noticed that for the same
processor (no matter what model) there are usually resuls that differ by a
factor or three or more, which simply cannot be correct unless the persons
made some serious setup mistakes...

    Thorsten

____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org


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From: Adin
Subject: Re: Mac newbie ...
Date: 21 May 2002 00:45:38
Message: <3ce9d0f2@news.povray.org>
Thanks Thorsten !

I didn't know that POV-Ray doesn't support Multi-Processor Systems. And
right now i'm quite amazed about my Mac. With only one processor running at
800 Mhz and a not optimized system i was about as fast as my PC :)

Thanks again.

I think i'm going to sell my PC =)

Anyways if anyone has more suggestions for optimizing a MacOs System please
tell me. I want to learn how to handle this machine.


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From: Y Tanabe
Subject: Re: Mac newbie ...
Date: 21 May 2002 02:50:24
Message: <3CE9EE37.470FC9E9@kh.rim.or.jp>
Dear Adin

I am using a Power Macintosh G3 (DT 233),
Mac OS 8.1J
CPU 233Mhz
Memory 160MByte

In my opinion is One machine use for Editing POV script,and other use for Rendering.
If you make compile POV-Ray 3.1g,Mega POV-Ray 0.7,
maybe you can make more fast rendering.
(1) Use more Memory Macro
(2) Stop Continue Trace,
Continue trace make both display and writing to disk for each rendering line.

Y.Tanabe
Kobe,Japan


Adin wrote:

> Thanks Thorsten !
>
> I didn't know that POV-Ray doesn't support Multi-Processor Systems. And
> right now i'm quite amazed about my Mac. With only one processor running at
> 800 Mhz and a not optimized system i was about as fast as my PC :)
>
> Thanks again.
>
> I think i'm going to sell my PC =)
>
> Anyways if anyone has more suggestions for optimizing a MacOs System please
> tell me. I want to learn how to handle this machine.


Post a reply to this message

From: Adin
Subject: Re: Mac newbie ...
Date: 21 May 2002 12:21:21
Message: <3cea7401$1@news.povray.org>
I got a problem with the memory too. POV-Ray takes about 700 mb of Ram, but
doesn't accept any more. It simply crashes if i try it.

Well as i said i'm a newbie i'm probably doing it wrong or something ...

I actually use my PC to modell in Moray and render the image on the Mac.


> Dear Adin
>
> I am using a Power Macintosh G3 (DT 233),
> Mac OS 8.1J
> CPU 233Mhz
> Memory 160MByte
>
> In my opinion is One machine use for Editing POV script,and other use for
Rendering.
> If you make compile POV-Ray 3.1g,Mega POV-Ray 0.7,
> maybe you can make more fast rendering.
> (1) Use more Memory Macro
> (2) Stop Continue Trace,
> Continue trace make both display and writing to disk for each rendering
line.
>
> Y.Tanabe
> Kobe,Japan


Post a reply to this message

From: Y Tanabe
Subject: Re: Mac newbie ...
Date: 21 May 2002 19:44:01
Message: <3CEADBC9.EA4EA2DE@kh.rim.or.jp>
Dear Adin

I set 128MB for MegaPOV-Ray 0.7.
Normaly Radiosity needs more memory after each rendering line.

Mac MegaPOV-Ray Home Page:
http://users.skynet.be/smellenbergh/

Y.Tanabe
Kobe,Japan

P.S.
MegaPOV-Ray 0.7 is faster than POV-Ray 3.1g.


Adin wrote:

> I got a problem with the memory too. POV-Ray takes about 700 mb of Ram, but
> doesn't accept any more. It simply crashes if i try it.
>
> Well as i said i'm a newbie i'm probably doing it wrong or something ...
>
> I actually use my PC to modell in Moray and render the image on the Mac.
>


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From: WhiteGandalf
Subject: Re: Mac newbie ...
Date: 1 Jun 2002 06:25:10
Message: <20020601122441833+0200@news.povray.org>
Well, I made some research 2 years ago under os classic and had long 
letters with Thorsten, who will maybe correct if I write some stupid 
things. Or maybe add something useful to my post, I would be pleased.



At that time I tried again and again, even recompiling MacPov myself. 
The conclusions were that CodeWarrior is decent, but not smart in code 
generation (looking at the assembler of some small test files the 68k 
code was crap, it works but uses your 68000 like a RISC making loads of 
stupid things and not using your powerfuil instructions) so I suspect 
similar pitfalls in PPC code, though my knowledge of that assembler is 
zero. I know that it has powerful instructions which other compilers 
don't have and so probably those don't get used well. But it's a guess. 
MacmegaPov was always FAST.
Using MegaPov I got results aligned with the speed I think my mac has, 
maybe sopme points slower but acceptable. Thorsten and me never got a 
comparatively fast official CodeWarrior compile. I asked the authours of 
megapov but never understood the up to 150% speed difference gap.

Now I got a G3, installed osX and was amazed about the speed of all 
things, also I learned a lot about compilers, HW architecture, RISC, 
pipelining and such stuff and so I had to try again some tests.

1. probaly the bench page is crap, the speeds there are just impossible 
I think, remember that just a small variation in the anti-alias setting 
can change things dramatically.

2. always remember to set "no verbose" and "don't display image", this 
can gain sometimes a considerable speed, as incredible as it seems.

3. be aware of back ground processes that eat up CPU (use proc viewer or 
top, I was astonished how much CPU an FTP can eat up)

so these were the premises.

Now the comparisons took place on the same g3 mac under osX. I used 
MegaPov (based on 3.1) which is as always amazingly fast.

I then got the unix sources and compiled a command line version of 
PovRay 3.1 using apple's compiler and comapred them to MegaPov. I used 
the same settings and run the tests on the same conditions.

apple uses gcc 2.95 or something around there
My conclusions confirm voices, gcc is not very smart or anyway the PPC 
backend is CRAP. I tried to optimize using every possible options, tried 
permutations, anything which had sense or not. I got a significant 
improvment over the original standard makefile settings but I was still 
slower than MegaPov!!!

gcc has no particular optimizations for your processor, it makes PowerPC 
generic code. This is incredibly stupid, the cache association, cache 
size and the internal architecture of the processors changed 
dramatically (and the G4 even more than my G2 and G3), even if G3 is 
backward compatible.
Using processor settings under CodeWarrior gives a significant 
difference. So I hope Apple will work on this to give us all a better 
gcc.

I tired then another experimental thing. FLOAT operations should be 
faster than DOUBLE and I wanted to try to compile pov in float and not 
double. I tried this by changing the header one time and the other by 
leaving the source unchanged and using the compiler flag "double as 
float".
Unfortunately the pov-code has a pitfall somewhere and the language 
parser corrupts, even using the compiler flag.
I am quite sure, even if I know nothing of pov internals, tha in many 
places floats could be used instead of doubles speeding things up (this 
would even give access to AltiVec) after all often the double precision 
and range will not be used.

Ric

PS: I have not tried official MacPov on  my G3 to compare, since I use 
os X only.

In <3ce8b77a$1@news.povray.org> Adin wrote:
> Ok guys ... maybe you can help me.

> Shouldn't the mac be faster in any case ? Does anyone have any ideas


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From: Thorsten Froehlich
Subject: Re: Mac newbie ...
Date: 1 Jun 2002 09:12:10
Message: <3cf8c82a@news.povray.org>
In article <20020601122441833+0200@news.povray.org> , WhiteGandalf 
<zus### [at] liberoit>  wrote:

> Using MegaPov I got results aligned with the speed I think my mac has,
> maybe sopme points slower but acceptable. Thorsten and me never got a
> comparatively fast official CodeWarrior compile. I asked the authours of
> megapov but never understood the up to 150% speed difference gap.

This is only with the preview on.  Turning the preview off and the difference
goes away as it is the same compiler and source code after all.  IIRC I
explained it back then...

    Thorsten

____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org


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