How to enable OpenCL?

Conan · Post by **Conan** » Mon Jan 14, 2013 10:05 am

Hi!

How to enable OpenCL? Only CUDA is visible.
Blender 2.65a
Windows 7 64-bit
Core i7 3960X
GTX580

On another computer with AMD graphic cards (AMD/ATI 5450, AMD/ATI 6570) I can't even set GPU rendering.

GPU Caps Viewer shows on every platform that OpenCL is available.

Regards!

Post by **stiv** » Tue Jan 15, 2013 7:01 pm

Not sure what your end goal is here, but CUDA is the better supported solution, both on nVidia cards and in Blender in general.

Conan · Post by **Conan** » Thu Jan 24, 2013 5:34 pm

My end goal is to use OpenCL:) CUDA is not available on AMD. I noticed that OpenCL is available on older releases including 2.63, 2.63a, 2.64, 2.64a, but it's not supported on 2.65 and 2.65a.

rty · Post by **rty** » Fri Jan 25, 2013 6:36 pm

OpenCL On hold

by the way suggesting Cuda over OpenCL it's just a downgrading, OpenCL is far more powerful than Cuda that is simply a framework for Nvidia GPUs; the real difference is that OpenCL requires more dedication and resources than Cuda to give/code an equivalent program, but in practice and in production OpenCL is always better.

Tehrasha · Post by **Tehrasha** » Fri Jan 25, 2013 7:11 pm

The recommendation of CUDA over OpenCL is based on which was currently better -supported- by Blender not which was more powerful in its potential capabilities.

Wokzombie · Post by **Wokzombie** » Sat Aug 10, 2013 10:38 pm

Fair enough, but it has limited relevance to the topic at hand.

I might just be crosseyed, but apart from a couple of information sources that say it is possible to enable OpenCL if I would really want to, I can't pin down more accurate information on the process.

Does anyone have any ideas or URLs to share?

I'm aware it'll burn a hole into another dimension where shaders are unicorns and out of memory errors will eat my innocence.

Tehrasha · Post by **Tehrasha** » Sun Aug 11, 2013 12:14 am

Wokzombie wrote: Does anyone have any ideas or URLs to share?

I'm aware it'll burn a hole into another dimension where shaders are unicorns and out of memory errors will eat my innocence.

I would suggest going over to http://graphicall.org
and search OpenCL, then try one of the builds available for your platform.

Like maybe this one... http://graphicall.org/110

Sadly...no unicorns.

Wokzombie · Post by **Wokzombie** » Sun Aug 11, 2013 12:28 am

Okay, that's something. I'll take a look around overthere.

Ignoring that I'm not on Windows, I don't see a reference to OpenCL at 'http://graphicall.org/110'.

Also, I got which environment the wiki meant with "The environment variable CYCLES_OPENCL_TEST can be defined to show it". They mean the OS environment and not Blender's, which I thought at first.

So starting Blender with

Code: Select all

CYCLES_OPENCL_TEST=true blender

is at least enough to turn it on in Blender. Now I just need to get it to actually render scenes with it, instead of rendering a black canvas.

Wokzombie · Post by **Wokzombie** » Sun Aug 11, 2013 12:37 am

Also, apparently this is the way to go in Windows:

1. Press Win + R, type CMD and press <enter>.
2. Go to your Blender folder. ex: cd C:\Program Files\Blender Foundation\Blender and press <enter>.
3. Type: set CYCLES_OPENCL_TEST=all and press <enter>.
4. And then start blender.exe.

Copied from here.

Tehrasha · Post by **Tehrasha** » Sun Aug 11, 2013 12:38 am

Wokzombie wrote: Ignoring that I'm not on Windows, I don't see a reference to OpenCL at 'http://graphicall.org/110'.

>- As of 57054 - Support for Cycles OpenCL, patch by Doug Gale & Brecht = Awesome !!! -<

Also, I got which environment the wiki meant with "The environment variable CYCLES_OPENCL_TEST can be defined to show it". They mean the OS environment and not Blender's, which I thought at first.

So starting Blender with
Code: Select all
CYCLES_OPENCL_TEST=true blender
is at least enough to turn it on in Blender. Now I just need to get it to actually render scenes with it, instead of rendering a black canvas.

If that works, thats great. I assumed it was a flag that needed to be set when building Blender from source.

Wokzombie · Post by **Wokzombie** » Sun Aug 11, 2013 1:24 am

Tehrasha wrote: >- As of 57054 - Support for Cycles OpenCL, patch by Doug Gale & Brecht = Awesome !!! -<

Haha, it's even one of the first lines.

Tehrasha wrote:If that works, thats great. I assumed it was a flag that needed to be set when building Blender from source.

Yeah, I remember reading something along those lines as well. Maybe that's another way of getting there. I'll check that in the future.