OTOY Forums

Hey guys, I'm new to the whole GPU render concept, as I'm sure many folk are, what are the limitations to GPU rendering?

I have read on another forum that the amount of Ram on ones video card could be an obstacle and thus scenes cannot be too complexed, is this so?

To the same question does it limit the maximum resolution that one can render? Or can other memory be called upon to assist? And does the option of a second card assist in lifting maximum res?

Hi,

The only limitations are video memory, eg you need to fit your scene into your GPU's memory.
although octane was developed in such a way that it tries to use the least possible memory necessary, it's still something that users need to watch out for, especially with small cards.

future GPU's coming in a few months will have lots more memory making use with octane much more flexible.

Radiance

Could you please give some sort of ratio of particular current card , scene size and render size.

What is the current limit for max ray bounces? What is the theoretical limit?

Oh and hi, my first post here. Well done on the progress to date, it's very impressive.

Hi there new community
Yes I'm interested to know too what you can do with say 896mb of a GTX275.
I read BbB at blenderartists.org saying he will probably use other renderers for heavy scenes and here, that 1gb enables far bigger scenes.
Can we have some indication of a render that will max out a 1gb gpu please.
Don't get me wrong octane looks great - I'm just curious about the practical sizes. 4096x4096 pixel images sounds fine..
Also if there are 2 cards used will that mean the scene size can be larger or just 2x (theoretical) speed?
Perhaps its better to experiment a little now and wait for a GTX380..

star wrote:Could you please give some sort of ratio of particular current card , scene size and render size.

sorry but that's all i have currently...

Radiance

Duz wrote:What is the current limit for max ray bounces? What is the theoretical limit?

Oh and hi, my first post here. Well done on the progress to date, it's very impressive.

preview default = 8, and there's no limit.
the user interface makes it max 64 at the moment but i can change that.

also keep in mind that russian roulette limits the actual depth in practice.
having maxdepth=1000 in an unbiased renderer will actually make your render only rarely exceed 16 bounces.

Radiance

pixelrush wrote:Hi there new community
Yes I'm interested to know too what you can do with say 896mb of a GTX275.
I read BbB at blenderartists.org saying he will probably use other renderers for heavy scenes and here, that 1gb enables far bigger scenes.
Can we have some indication of a render that will max out a 1gb gpu please.
Don't get me wrong octane looks great - I'm just curious about the practical sizes. 4096x4096 pixel images sounds fine..
Also if there are 2 cards used will that mean the scene size can be larger or just 2x (theoretical) speed?
Perhaps its better to experiment a little now and wait for a GTX380..

hi,

you'll just have to wait a few days and play with octane to have a feel for what it takes to fill up a GPU memory wise...

Radiance

Yep I really hope that Memory doesn't become a problem.
It's like going from 64bit OS back to 32bit, that would drive me nuts.

But theses new Tesla cards have a lot of RAM, just pricey.

cheers