I just bought the mac book pro with the AMD Radeon R9 M370X. Unfortunately rendering is quite slow. I've read in different forums that i need to switch to GPU in user preferences -> system and change to GPU computing on the right hand side of the screen. I did it but the rendering process is still slower than rendering with just cpu. Can sb tell me what i am doing wrong? Thanks a lot!! Marc
With GPU rendering it's usually best to increase the tile size to about 256x256. That way you're not going to-and-from CPU and GPU memory so much.
there seems to be a big difference between nvidia graphic cards and amd graphic cards. Until recently Gpu rendering was only possible using the nvidia cards with cuda cores. Starting with blender 2.75 / 2.76 it should also be possible with OpenGL amd cards. But with restrictions, I believe. Being an apple fan myself it is still a bit of a mystery for me too with is exactly the status of blender Gpu rendering on Mac / amd hardware. It is my understanding that fast Gpu rendering is still a nvidia / Windows privilege