OTOY Forums

I saw that you noted that OpenCL isn't as mature as CUDA for what you're doing and I was wondering what specifically you meant by it. Is it an IDE thing (cross-platform GUI dev) or the actual languages. I know that Chaos Group is working on porting their CUDA V-RayRT permanently to OpenCL and I have this unbiased SmallLuxGPU render benchmark that also uses OpenCL so I'm just wondering what the issue is, especially since you said that you had to rework a lot of code for multi-GPU support, which you get for free with OpenCL. I have been playing around with dual graphics cards in my Mac Pro and all the OpenCL stuff just uses them all (and the CPUs too, if you want):

http://grab.by/grabs/bc6ebe69c796d83714 ... 928219.png

Anyway, I'm not a programmer so I was wondering if this was a real barrier for you or just something you (understandably) don't want to revisit.

It's slow, very very slow.
I'm also not sure about it's future.

CUDA works fast and now, and octane development was started when opencl did'nt exist yet.
Anyways, once i see some numbers (the smalluxgpu's ones are horrible) we can do a port to opencl, it is not that much work.

Radiance

Hi!
I'm not programmer too, but I have the feeling the "pure" CUDA-GPU Octane approach is the best as for today. Of course this doesn't mean it will be so for the future, and I think people at Refractive Software have their good reasons for choosing a platform that cut off a half of their potential customers (i.e. ATi powered people).

@cgbeige: from a quick look at your statistics under SLG I think there's something wrong with your settings... your 4870HD is twice as faster than your GTX285 and I don't think this is right (imho).

GTX275(lower model than GTX285) is faster than HD5870(higher model than 4870) .. See 03 and 04 ..

http://www.luxrender.net/forum/viewtopi ... e8d5511ca1

ya, I noticed the slower GTX 285 score. Anyway, my second GTX 285 arrives today so I won't bother trying to figure out what the problem is there. Mixing GPUs is just a bad idea in my opinion, even on OSes that are relatively good at it, like OS X.

Thanks for the response radiance. Good to hear it from someone who knows what they are talking about.