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Little Memory use

Posted: Mon Nov 10, 2014 8:48 pm
by Almfeldt
Hello im A newbie her just bought and trying to learn Octane.
My first issue:

Im running on dual Geforce GTX 760 4gb memory.
When look at Octane render Viewport it says i use 199mb memory and that i have 4096mb total.
1: Why dose Octane not use more memory 2: Were is the rest of the memory(Dual cards 4096x2)

Re: Little Memory use

Posted: Mon Nov 10, 2014 9:37 pm
by rappet
Hi,
It does not need to use all your memory as for max speed or anything...
The vram is the max available to load your scene
. Your scene now is 199mb.. If you add objects or enlarge resolution ie, your scene will get bigger and the vram will be used more loading the scene. Id your scene is larger then 4 gb it will not be able to load in your available vram and you cannot render.
Try and enlarge your render resolution as a test.. When having lagrer resolution (i.e. 4000x2000px px instead of 1200x600 px)
You will see that your vram is used with larger number.
I hope this is a good explanation?
Greetz,

Re: Little Memory use

Posted: Mon Nov 10, 2014 10:48 pm
by Almfeldt
Thanks for your answer.
Just to make sure we are talking about the graphic cards memory right?
And in that case, is the memory only important when i start the render?(Scene size)

Im used to Maxwell render and image size there realy slows the render time.Is it the same with Octane?

Guese i need to watch some tutorials.. :)

Re: Little Memory use

Posted: Mon Nov 10, 2014 11:22 pm
by rappet
Almfeldt wrote:Thanks for your answer.
Just to make sure we are talking about the graphic cards memory right?
And in that case, is the memory only important when i start the render?(Scene size)

Im used to Maxwell render and image size there realy slows the render time.Is it the same with Octane?

Guess I need to watch some tutorials.. :)
Yes, I am talking about graphic memory card as well.

I do not know the details about how the memory is specifically important when loading, rendering or otherwise.

I do not know about Maxwell
I have read just little about Maxwell (as render engine for Artlantis Render), but I did not go there because of the slowness...
Slowness of the render engine, but also the slowness of the development in CPU (compared to GPU)
But I can tell that in Octane larger resolution size ofcourse takes longer rendertime then small resolution size... Every render software will be slower when having to render more pixels.
Have fun watching the tuts ;)

Re: Little Memory use

Posted: Mon Nov 10, 2014 11:39 pm
by rappet
I like charts:
This one is gpu versus cpu
http://extrahardware.cnews.cz/sites/def ... gpucpu.jpg

Re: Little Memory use

Posted: Tue Nov 11, 2014 12:14 am
by grimm
Almfeldt wrote:Hello im A newbie her just bought and trying to learn Octane.
My first issue:

Im running on dual Geforce GTX 760 4gb memory.
When look at Octane render Viewport it says i use 199mb memory and that i have 4096mb total.
1: Why dose Octane not use more memory 2: Were is the rest of the memory(Dual cards 4096x2)
Hi Almfeldt,

You can not just add the memories together unfortunately. :) Each card must be considered to be a separate compute device as they can't talk to each other. When Octane uses the cards it copies the scene's geometry, textures, and the kernels to each one. They run independently generating the image and Octane will pull the image data off of the cards at regular intervals, merging them to display. This is a good thing and it's why Octane's performance is almost linear when you add more cards of the same type. If they talked to each other and shared memory the rendering would be slower. This is the big reason why when you add more CPU cores the speed increase is not as linear as with GPU's, they have to share the system's memory, bus, etc.