When I render out a scene with multiprocessing enabled I get an error on the status/info pallet saying 'Incompatible Artisan: Multiprocessing disabled.
The render continues, but slower. I have this on both my PC (Q6600, 4GB, HD6850) and my Mac (Mac pro 2008).
Is this normal or is something wrong? Mind you: I do not use any opscure plugins. This happens all the time when rendering using multiprocessing with even the simplest scenes. Both classic 3D and Raytrace 3D.
It's normal for Raytrace 3D, it may not be normal for the conventional 3D. Still, even then it could be "as designed". Impossible to know without knowing the exact setup of your scene, no matter how simple you think it may be otehrwise. You could still be using one specific feature that casues this.
Mylenium is correct.
A simple way to think of it is this: The Render Multiple Frames Simultaneously multiprocessing feature relies on having a separate rendering process on each of several CPUs. But you only have one GPU, so that can't happen in the same way on the GPU.
Probably a little late to this topic, but it's worth pointing out that it looks like anything pre-composed should not be using the Ray-traced 3D renderer either. Even if there is nothing in the scene that uses those features, it will still deactivate multiprocessing. Make sure all your nested compositions use the Classic 3D renderer.
A little frustrating, but maybe can be addressed in an update or future version (hello, CS6 subscription updates?).