Hi all,

is it normal for PovRay 3.7 to max all of my 4 cores on an Intel Q9450 to 100%
for the duration of the render?

It does render stuff pretty quick (renders the advanced/balcony example in under
a couple of minutes) but maxing everything at 100% is a tad worrying and the CPY
temp rises along with it.

On PovRay 3.6, when I render advanced/balcony it uses about 35% of the total CPU
usage (Core1: 80%, core2: 30%, core3: 15%, core4: 15% [rough figures based on
graph])

The temp on the CPU hardly moves when using PovRay 3.6.

Does this sound like a bug in 3.7?

thanks

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"Stonefox" <the### [at] hotmailcom> wrote in message 
news:web.486b13f5a188e85371ee1c30@news.povray.org...
> Hi all,
>
> is it normal for PovRay 3.7 to max all of my 4 cores on an Intel Q9450 to 
> 100%
> for the duration of the render?

I think that's the whole idea of POV-Ray 3.7

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com

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> I think that's the whole idea of POV-Ray 3.7
>
> cu!


The whole idea of 3.7 is to max out every cpu to 100%? That doesnt do much for
multitasking, not to mention the CPU heat rise.

3.6 Doesnt max 100% of 1 processor.

If its meant to do it, then fair enough, just seems a bit silly to take up every
processor in the machine to render (at 100%) unless there is a setting to change
the render process priority.

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> If its meant to do it, then fair enough, just seems a bit silly to take up 
> every
> processor in the machine to render (at 100%) unless there is a setting to 
> change
> the render process priority.

I think you can set the process priority in the render menu.

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"Tim Attwood" <tim### [at] comcastnet> wrote:
> > If its meant to do it, then fair enough, just seems a bit silly to take up
> > every
> > processor in the machine to render (at 100%) unless there is a setting to
> > change
> > the render process priority.
>
> I think you can set the process priority in the render menu.

So do you all think I'm worrying over nothing then? ;)

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Stonefox wrote:
> The whole idea of 3.7 is to max out every cpu to 100%? That doesnt do
> much for multitasking, not to mention the CPU heat rise.

A correctly installed CPU does not overheat if all its cores are used to
100%. Otherwise it wouldn't make much sense to have multiple cores in a
CPU, right?

Post a reply to this message

Stonefox wrote:
> The whole idea of 3.7 is to max out every cpu to 100%? That doesnt do
> much for multitasking, not to mention the CPU heat rise.
> 
> 3.6 Doesnt max 100% of 1 processor.

I took a look at the UNIX source code of povray-3.7.0.beta.25b. I found
in source/frontend/processrenderoptions.cpp the following line (line
257):

{ "Work_Threads", kPOVAttrib_MaxRenderThreads, kPOVMSType_Int },

This is probably the ini option you are looking for.

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"Stonefox" <the### [at] hotmailcom> wrote in message 
news:web.486b4650a80bdc7f440d83f10@news.povray.org...
> "Tim Attwood" <tim### [at] comcastnet> wrote:
>> > If its meant to do it, then fair enough, just seems a bit silly to take 
>> > up
>> > every
>> > processor in the machine to render (at 100%) unless there is a setting 
>> > to
>> > change
>> > the render process priority.
>>
>> I think you can set the process priority in the render menu.
>
> So do you all think I'm worrying over nothing then? ;)

In version 3.6 for Windows there are two options on the 'Render' menu for 
controlling this; the Render Priority can be set to avoid it dominating the 
machine and the 'Duty Cycle' setting for "unusual cases of heat 
accumulation".  Are you saying that they don't work or aren't there in 3.7 
beta 27? or that you can't get them working?

Regards,
Chris B.

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Stonefox <the### [at] hotmailcom> wrote:
> The whole idea of 3.7 is to max out every cpu to 100%?

  In the exact same way as the idea with previous versions has been to
max out a single cpu to 100%.

  What do you expect? POV-Ray is a rendering software. By default it uses
all the available resources.

> That doesnt do much for multitasking

  100% CPU usage doesn't mean that nothing else *can* use the CPU. It means
nothing else is *using* the CPU *currently*.
  I think this is a rather curious misconception some people seem to have.

  Just start another CPU-heavy program and you'll see that the OS nicely
shares the available CPU resources among them. POV-Ray doesn't have to
share CPU with anybody. The OS will force it to share.

  Also in most OSes you can set priorities to processes. If you give a low
priority to POV-Ray, it will take 100% when it can, but if some other process
requests the CPU, it will get more of it.

> not to mention the CPU heat rise.

  If your computer is built properly it should stand 100% CPU usage for
days continuously without problems.

> 3.6 Doesnt max 100% of 1 processor.

  Not because it would somehow deliberately avoid doing so. It's just that
the OS and other processes do something else at the same time, so POV-Ray
doesn't get everything.

> If its meant to do it, then fair enough, just seems a bit silly to take up every
> processor in the machine to render (at 100%)

  I honestly cannot understand how that is "silly". That's precisely the
whole idea in multithreaded rendering: To use *all* the available resources
to render faster. Most modern renderers do that, and if any renderer doesn't,
it's considered old.

  And you *can* make POV-Ray use less threads if you want. There's an option
for that.

-- 
                                                          - Warp

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"Stonefox" <the### [at] hotmailcom> wrote:

> is it normal for PovRay 3.7 to max all of my 4 cores on an Intel Q9450 to 100%
> for the duration of the render?

as they say: it's not a bug it's a feature!

or to be more direct: RTFM!

What you call a bug has been a huge effort to implement and get running
efficiently, namely using all available resources of modern PCs to speed up
rendering.

And what you write about 3.6 using only parts of the each CPU core is the OS
doing it's job. You might see that the total CPU usage of 3.6 will be 25% on a
quadcore, which is exactly one core @100%.

also you can set the number of threads running, which means if you set this to 3
you'll have one core free for other stuff.

Greetings
Aydan

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