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Multi GPU

Posted: Mon May 13, 2013 9:01 pm
by ravenzep
Hello!

When is that coming? We are in the middle of 2013. And i see on the forum its been mentioned sometime in 2011. I mean for us users that have multiple gpu. It seems that this renderer isn't quite "cost effective" now is it?

LuxRender can already do MultiGPU bi directional rendering. :)

Re: Multi GPU

Posted: Wed May 15, 2013 5:50 am
by OnoSendai
Hi ravenzep,
We are working on having the capability in Indigo to do almost all of the computation on the GPU. When we have this multi-GPU support will work much better and should follow shortly.

Until then there's not much point as the CPU is usually the bottleneck.

Re: Multi GPU

Posted: Wed May 15, 2013 9:28 am
by ravenzep
Thats bloody Fantastic. Will it be able to handle large datasets / meshes? Or is it bound to GPU memory like the rest of the GPU renderers?

Re: Multi GPU

Posted: Wed May 15, 2013 9:39 am
by OnoSendai
It will definitely be bound to GPU memory at first. We may look into something more complicated later :)

Re: Multi GPU

Posted: Wed May 15, 2013 9:43 am
by ravenzep
But why not let Indigo customers decide if they want to render out of core or not, based on scene size :)

Small scenes = fast , BIG scenes = a bit slower

Re: Multi GPU

Posted: Wed May 15, 2013 11:21 pm
by Juju
ravenzep wrote:But why not let Indigo customers decide if they want to render out of core or not, based on scene size :)

Small scenes = fast , BIG scenes = a bit slower
you already have the render affinity choice, CPU or GPU. CPU handles all render type options, GPU only a few.

Re: Multi GPU

Posted: Thu May 16, 2013 1:52 am
by ravenzep
What you don't know is that OpenCL on the CPU runs faster than pure C++ on the cpu. LuxRender proves that pretty good.

Re: Multi GPU

Posted: Thu May 16, 2013 3:29 am
by Zom-B
ravenzep wrote:What you don't know is that OpenCL on the CPU runs faster than pure C++ on the cpu. FluxRender proves that pretty good.
No it doesn't!

Re: Multi GPU

Posted: Thu May 16, 2013 11:36 pm
by PureSpider
What LuxRender proves is that their devs can fool their users pretty well 8)

Re: Multi GPU

Posted: Fri May 17, 2013 12:09 am
by galinette
ravenzep wrote:What you don't know is that OpenCL on the CPU runs faster than pure C++ on the cpu. FluxRender proves that pretty good.
An example is not a proof...

Also, since OpenCL on the CPU is, internally, a pure C++ implementation, we could rewrite the sentence "¨Pure C++ on the cpu runs faster than pure C++ on the cpu", which sounds weird :)
No it doesn't!
Well sometimes it does, if the base c++ implementation is poorly optimized. OpenCL tends to force to think parallel, which sometimes helps.

Re: Multi GPU

Posted: Fri May 17, 2013 12:57 am
by ravenzep
Gotta love when artists talk about C++...

Anyway Multi GPU isn't coming anytime soon for Indigo users :)

Re: Multi GPU

Posted: Fri May 17, 2013 1:52 am
by OnoSendai
Show some respect to the forum users ravenzep, or I will ban you.

Re: Multi GPU

Posted: Fri May 17, 2013 2:30 am
by William
Luxrender doesn't have full opencl rendering mode anyway. It has hybrid path rendering with opencl (ray intersections).
Then it has a completely seperate render engine called SmallLuxGPU (SLG), which is an opencl engine with a smaller feature set than that of Luxrender (but samples much quicker) and reads Luxrender scene files.
Luxrender is pretty good engine but it's slow (even with hybrid). Indigo probably 2-3x quicker (or more in some cases).

Re: Multi GPU

Posted: Fri May 17, 2013 4:14 am
by galinette
ravenzep wrote:Gotta love when artists talk about C++...
And, you know, I'm not even an artist 8)

Re: Multi GPU

Posted: Fri May 17, 2013 9:26 pm
by CTZn
galinette wrote:
ravenzep wrote:Gotta love when artists talk about C++...
And, you know, I'm not even an artist 8)
Brag not, you senior coder !