Nicolas Alvarez <nic### [at] gmailisthebestcom> wrote:
> In fact, I think if preview is off, it only needs width*2 memory (plus 
> width*something used by libpng), not width*height.

  I believe pov3.6 and earlier wrote each rendered scanline to the
image file and then dropped it. Thus it required memory only for one
scanline at a time, which allowed rendering enormous images even in
computers with a small amount of memory.

  In pov3.7, because of the distributed rendering, things have changed
a bit: There are no individual scanlines anylonger. I don't really know
if the entire image is now kept in memory (when there's no preview) or not.
Chris or Thorsten would be much more qualified to answer this.

-- 
                                                          - Warp

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Warp escribió:
> Nicolas Alvarez <nic### [at] gmailisthebestcom> wrote:
>> In fact, I think if preview is off, it only needs width*2 memory (plus 
>> width*something used by libpng), not width*height.
> 
>   I believe pov3.6 and earlier wrote each rendered scanline to the
> image file and then dropped it. Thus it required memory only for one
> scanline at a time, which allowed rendering enormous images even in
> computers with a small amount of memory.

It definitely needs *two* scanlines, not one. Antialiasing requires 
comparing the pixel color with the one above ;) I remember seeing that 
in the code.

I just didn't know if somewhere *else* in the code, POV kept the whole 
image in memory. Thanks for confirming it doesn't.

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> 40 megapixels = 40,000,000 pixels.
> 40,000,000 pixels / 2 pixels/second = 20,000,000 seconds.
> 20,000,000 seconds = 333,333 minutes.
> 333,333 minutes = 5,555 hours.
> 5,555 hours = 231.5 days.
> 

Hmm let's see what's available on the farm.

 > Sum of available disk space on these hosts: 8662.28 GB
 > Sum of memory on these hosts: 211062.96 MB

Bah, no aggregate information about CPU power...

These *four* 8-core Xeon computers seem too similar. Might be duplicate 
entries (same computer)... *gets into admin interface* Nope! Different 
hostnames.

How big are your sources? :)

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Nicolas Alvarez wrote:

> Hmm let's see what's available on the farm.

Ooo, I didn't know you were a farmer?

> These *four* 8-core Xeon computers seem too similar. Might be duplicate 
> entries (same computer)... *gets into admin interface* Nope! Different 
> hostnames.
> 
> How big are your sources? :)

About 3 KB?



Actually, reminds me of something I saw this morning. Some guy saying 
there's basically "no point" in adding more CPUs to the Folding@Home 
project, because a single GPU is something like 50x faster while using 
less electricity...

All I need know is for that guy who's writing a CUBA backing for GHC to 
finish his PhD, and then I can implement my own raytracer in Haskell and 
achieve world domination. Wahahahahaha!! >:-D

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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> Nicolas Alvarez wrote:
>> Hmm let's see what's available on the farm.
> 
> Ooo, I didn't know you were a farmer?

I meant "render farm"...

>> How big are your sources? :)
> 
> About 3 KB?

Send me them and I'll see what comes out of the Xeons.

> Actually, reminds me of something I saw this morning. Some guy saying 
> there's basically "no point" in adding more CPUs to the Folding@Home 
> project, because a single GPU is something like 50x faster while using 
> less electricity...

There's many processes done by Folding@Home that can only be done in 
CPUs. GPUs are the fastest but least flexible (= can run a limited 
subset of algorithms) for the Folding project.

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Invisible wrote:
> 40 megapixels = 40,000,000 pixels.
> 40,000,000 pixels / 2 pixels/second = 20,000,000 seconds.
> 20,000,000 seconds = 333,333 minutes.
> 333,333 minutes = 5,555 hours.
> 5,555 hours = 231.5 days.

hope it's not another RSOCP! ;)

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Nicolas Alvarez wrote:

> 40 megapixel? Hmm how much RAM is it eating? Last time I tried an image 
> around that big, POV-Ray crashed.

Virtual size 144 MB.
Private bytes 98 MB.
Working set  102 MB.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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Invisible <voi### [at] devnull> wrote:
> ...you ask POV-Ray to draw a 40 megapixel image, it renders at roughly 2
> pixels per second, and you calculate how long it will take to render.
>
> And then feel glad you're sitting down. (!)
>
>
>
>
>
>
>
>
>
>
> 40 megapixels = 40,000,000 pixels.
> 40,000,000 pixels / 2 pixels/second = 20,000,000 seconds.
> 20,000,000 seconds = 333,333 minutes.
> 333,333 minutes = 5,555 hours.
> 5,555 hours = 231.5 days.
>
> --
> http://blog.orphi.me.uk/
> http://www.zazzle.com/MathematicalOrchid*

I can't believe I'm the first one asking this, but...

....what the HE** do you need a 40 MP image for?!?!?

Assuming 16:9 proportions, that's like 8400x4725, or 28"x15" at 300DPI.

Or, if its a 4:3 image, then it's like 7300x5475, or 24"x18" at 300DPI.

That's a REALLY nice print :)

....Chambers

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> I can't believe I'm the first one asking this, but...

I guess most other POVers didn't think it was anything strange :)

I *have* tried such size of image with William Tracy's image.

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Chambers wrote:
> I can't believe I'm the first one asking this...

hey, I don't argue with nuts.  If he wishes to dump his CPU on a 
year-long render, go ahead.  :)

Perhaps he's willing to break the Guiness record on "Most pointless and 
wasteful povray render ever".  Mine was just a 3 day render of some 
glass cups... :P

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