POV-Ray : Newsgroups : povray.pov4.discussion.general : Another v4.0 rtr/kla concern. Memory bubble with large HDRI images. : Re: Another v4.0 rtr/kla concern. Memory bubble with large HDRI images. Server Time
18 Oct 2021 16:29:26 EDT (-0400)
  Re: Another v4.0 rtr/kla concern. Memory bubble with large HDRI images.  
From: William F Pokorny
Date: 7 Oct 2021 06:47:57
Message: <615ed05d$1@news.povray.org>
On 10/7/21 4:09 AM, Kenneth wrote:
> "Kenneth" <kdw### [at] gmailcom> wrote:
> 
>>
>> I ran a series of thread tests, with the preview display OFF, and got some
>> interesting and mysterious results.
>>
> 
> Well, I'm getting some screwy results now. Just when I thought that my previous
> tests were 'definitive' (more or less), some *new* and mysterious behavior
> arises.
> 
> I just ran one of my 'typical' older (v3.8) scenes that I had already set up for
> kla/rtr, with an almost identical #while-loop camera like my 'bare' test, and
> with image_maps, objects, lights, etc. And I used all 8 cores/16 threads of my
> machine, AND turned the preview display ON...
> 
> ....And that scene runs with NO increase in memory, loop after loop! I don't get
> it. I feel like I'm comparing bananas to footballs, with no logical basis for my
> tests. :-<  If anything, *that* scene should trigger the increase in memory, not
> my 'bare' scene.
> 
> Here's *another* screwy thing (which may be Windows-specific?):
> Assume that I have turned both of these off:
> preview display OFF
> output file OFF
> 
> In POV-ray's GUI, I have to choose *some* particular render resolution (which
> gets chosen from my 'quickres.ini' file) to run a scene-- even though there is
> now NO image output and NO preview. But I discovered that the res I pick *does*
> affect the fps speed of the looping animation. Running my 'bare' test scene with
> 8 cores/16 threads, this is what happens:
> At 160X120 res:   90fps (!)
> At 1280X960 res:  9.5fps
> 
> I didn't realize this earlier. And I have not yet determined if this ghostly
> change-of-res (AND fps rate) affects how the memory use increases...or does not
> increase.
> 
> Madness!
> 
Hmm, Alright. Thank you for the data. I'm seeing odd results too. There 
are reasons - and likely a mix on them. We just don't know at the moment 
what the reasons are!

The only sure thing I see is slowing down the frame rate helps with the 
memory bubble. I've got and itch / vague recollection of having run 
across code comments about some memory handling trade off with rtr/kla.

Aside: I believe the entire reason the real time / continuous render 
options were created was to show off multiple core / hyper threaded 
CPUs. IIRC Thorsten and Chris did it in a hurry and it's more or less 
been in that demo state since.

FYI - I'm busy with real life until early to mid next week.

Bill P.


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