Yes, I've read this post already. But it didn't work. Now I'm looking for more information and ways to diagnose the problem... and perhaps find a solution.
The base system is an Ubuntu machine (14.04 LTS), 64 bit, and a GTX 970.
The GTX 970 is a "rather new" card and is not supported by the proprietary nvidia driver that "comes" with 14.04. You have to install version 343.22 which is available via the xorg/edgers ppa repo.
Additionally, as mentioned here, the utility nvidia-moprobe has to be installed, to give non-root users access to CUDA.
Furthermore, they also recommend to install the newest development build from https://builder.blender.org/download/, as 2.72b does not support the GTX 970/980 (no idea why), and to install CUDA 6.5 from nvidia for the CUDA 6.5 toolkit.
I've done all this, but it's still not working. Along the way, I came across some conflicting information, which I hope some of you can clarify.
I've read on various sites, that the GTX 970/980 is only supported starting from nvidia driver 343.22, and CUDA 6.5. So I think this is a given fact.
Which means, that I can't use the CUDA library from the main Ubuntu repo, which is v5.5.
In some postings I've read that the builds from the buildbot contain a pre-compiled CUDA kernel and installing the CUDA toolkit is not necessary, in other places a CUDA update is recommended for better performance.
There is an Ubuntu bug report regarding the nvidia-modprobe, however I have no idea if this also relates to Blender.
Apparently the current Blender build (2240c26, Nov. 28, 2014) does not recognize the GTX 970 in the described configuration.
The nvidia-settings utility confirms that 343.22 is running on my system. And the GTX 970 is listed there.
My questions are:
- Does the builderbot version come with a CUDA kernel and if so, is it 6.5 compatible? If not, is there a way to tell Blender to use the external toolkit (short of compiling from source)?
- Which devices does Blender use under Linux to access CUDA? I.e. is nvidida-modprobe necessary, and if so, how can I tell that it is working?
- What does the developer build have, that 2.72b hasn't, that is needed here?
- Are there any switches when starting blender, that might shed some light why it does not use CUDA?
Thank you for reading this far :) - any help is welcome.