OpenCL Port for Thea Presto (wip)

[giannis]

How would you say the current OpenCL port compares to CUDA speed? Does it have the potential to equal / surpass it in terms of performance?

Theoretically speaking, the expectation is that going with a more direct way (Presto CPU or proprietary CUDA) will give better performance compared to OpenCL. From there on, unless we have a stable build and tune it (i.e. optimizing it as much as we did with the other APIs) the comparison will not be fair, so it is only a qualitative index now.

Best wishes

[Slinger]

That's amazing news.

[ivan.dedos]

great news!

[Javadevil]

Wow thats one mean feat !! nice work !

I wonder how the new nvidia 980's will go with OpenCL ? From what I have scene the luxmark bench marks look impressive.

cheers

[giannis]

I can say already (after a few tests) that going with CUDA for NVidia produces faster results than going with OpenCL. Although, the OpenCL port is not as optimized yet, this is to be expected because OpenCL is one layer more abstract than CUDA (compilation goes through CUDA as far as I know).

Best wishes

[GreenUser]

Great work! From what I heard about Open CL I thought it would be almost impossible to do. I would have thought it to be simpler to get Thea working with intel phi than Open CL from what I read.

It's exciting to know that when done we can compare Nvidia to AMD. Do you know yet if there will be a minimum AMD GPU we will need for it to work or will something old like a Radeon 8500 or 4770 work?

[PixelMango]

I can say already (after a few tests) that going with CUDA for NVidia produces faster results than going with OpenCL. Although, the OpenCL port is not as optimized yet, this is to be expected because OpenCL is one layer more abstract than CUDA (compilation goes through CUDA as far as I know).

Best wishes

CUDA is faster (than OpenCL) when using VRay RT in GPU mode. CUDA is Nvidia's dedicated tech, so why wouldn't it be more efficient than an Open Standard.

[eph]

I can say already (after a few tests) that going with CUDA for NVidia produces faster results than going with OpenCL. Although, the OpenCL port is not as optimized yet, this is to be expected because OpenCL is one layer more abstract than CUDA (compilation goes through CUDA as far as I know).

Very understandable. Plus they probably prefer optimising CUDA than OpenCL

What about technical possibilities, would it be easier / more difficult to develop i.e. Displacement in OpenCL..?

[giannis]

I can say already (after a few tests) that going with CUDA for NVidia produces faster results than going with OpenCL. Although, the OpenCL port is not as optimized yet, this is to be expected because OpenCL is one layer more abstract than CUDA (compilation goes through CUDA as far as I know).

Best wishes

CUDA is faster (than OpenCL) when using VRay RT in GPU mode. CUDA is Nvidia's dedicated tech, so why wouldn't it be more efficient than an Open Standard.

Exactly!

[giannis]

I can say already (after a few tests) that going with CUDA for NVidia produces faster results than going with OpenCL. Although, the OpenCL port is not as optimized yet, this is to be expected because OpenCL is one layer more abstract than CUDA (compilation goes through CUDA as far as I know).

Very understandable. Plus they probably prefer optimising CUDA than OpenCL

What about technical possibilities, would it be easier / more difficult to develop i.e. Displacement in OpenCL..?

In Presto framework, it poses the same level of difficulty from the pure development side but if you add more things to the mix (like optimization, debugging tools and others), again a dedicated tech will make the whole job easier.

Best wishes