POV-Ray : Newsgroups : povray.macintosh : Pov 3.5 OSX - not 100% CPU Server Time
22 Dec 2024 16:27:02 EST (-0500)
  Pov 3.5 OSX - not 100% CPU (Message 1 to 4 of 4)  
From: Jonathan Morton
Subject: Pov 3.5 OSX - not 100% CPU
Date: 11 Jul 2002 16:41:08
Message: <3D2DDEE3.40203@chromatix.demon.co.uk>
Having just installed POV-Ray 3.5 on my PowerBook G3, running MacOS 
10.1.5, I was a bit surprised to see it using only about 50-70% CPU, 
even with nothing else running and the "Friendliness" set to 
"Tyrrannical".  This seems to be independent of whether Preview is 
switched on, or the particular scene file in use.

Is anyone else seeing this?


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From: Thorsten Froehlich
Subject: Re: Pov 3.5 OSX - not 100% CPU
Date: 13 Jul 2002 04:03:53
Message: <3d2fdee9@news.povray.org>
"Jonathan Morton" <chr### [at] chromatixdemoncouk> schrieb im Newsbeitrag
news:3D2### [at] chromatixdemoncouk...
> Having just installed POV-Ray 3.5 on my PowerBook G3, running MacOS
> 10.1.5, I was a bit surprised to see it using only about 50-70% CPU,
> even with nothing else running and the "Friendliness" set to
> "Tyrrannical".  This seems to be independent of whether Preview is
> switched on, or the particular scene file in use.
>
> Is anyone else seeing this?

This is normal. Under Mac OS X no application may hog the whole CPU.
Thus POV-Ray cannot get as much CPU time as under Mac OS 9.  For this
reason the documentation/requirements recommend using Mac OS 9 for
maximum render speed.

    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: Jonathan Morton
Subject: Re: Pov 3.5 OSX - not 100% CPU
Date: 16 Jul 2002 23:53:22
Message: <3D34DBA9.1000206@chromatix.demon.co.uk>
>>Having just installed POV-Ray 3.5 on my PowerBook G3, running MacOS
>>10.1.5, I was a bit surprised to see it using only about 50-70% CPU,
>>even with nothing else running and the "Friendliness" set to
>>"Tyrrannical".  This seems to be independent of whether Preview is
>>switched on, or the particular scene file in use.
>>
>>Is anyone else seeing this?
> 
> This is normal. Under Mac OS X no application may hog the whole CPU.
> Thus POV-Ray cannot get as much CPU time as under Mac OS 9.  For this
> reason the documentation/requirements recommend using Mac OS 9 for
> maximum render speed.

I would expect this if other applications were using the CPU, but they 
aren't - there's 30-40% CPU completely unused.  Other Carbon-based apps 
are able to use 100% (or close to that figure) as required.


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From: Thorsten Froehlich
Subject: Re: Pov 3.5 OSX - not 100% CPU
Date: 17 Jul 2002 06:17:55
Message: <3d354453@news.povray.org>
In article <3D3### [at] chromatixdemoncouk> , Jonathan Morton 
<chr### [at] chromatixdemoncouk>  wrote:

> I would expect this if other applications were using the CPU, but they
> aren't - there's 30-40% CPU completely unused.  Other Carbon-based apps
> are able to use 100% (or close to that figure) as required.

The problem is that rendering is done in a cooperative thread, which means
if that thread takes over the CPU for more than two seconds, POV-Ray will
get blocked by Mac OS X.  As it is not predictable how long the next pixel
will take, the proper way to avoid this is to give time to other cooperative
threads after every pixel.  This should never be a problem:

Of course, Mac OS X should still automatically return the unused time to
POV-Ray, but it fails to do so.  This is a bug in the Mac OS X threading of
Carbon applications, unfortunately :-(

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org


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