oh, smart ones,
I have a scene with 12,405 vertices and 9,766 faces which is a kitchen I'm designing for our house. I'm using Blender 2.76 on OS X 10.11.2 on an iMac Retina.
First, rendering quality: My samples are set to 18 square samples for 324 AA passes. I am using the Progressive Refine with 64x64 tiles. Rendering quality is basically like a 120000 ISO on a digital camera - very, very grainy. My "camera" sensor is set to 35mm DSLR.
I have no Blender Phong lights in my scene, everything is set for Emission material, with 7 object light sources, trying to replicate the existing, real-world kitchen. The material's Emission light strength is 11 for Surface and 7 for Volume. I have attached one such render output.
I have read most other questions that have to do with "grainy cycles, help!" or "fireflies, help!", but none of the fixes suggested there actually visibly improved the quality (of course samples helps, but when I bumped sampling to some large number I ended up with unrealistic times). Why don't we see any graininess in e.g. Sintel?
Second, rendering time: I have played with CPU rendering (8 threads since I have 8 cores), and also GPU rendering (this is my ATI video card). Overall, there is not much speed difference between my CPU and my GPU and both have extremely long times to render. For the 300+ samples above, I end up with about 40 minutes render time.
So, I said, it's definitely glass, reflections and what other complex objects I have in my scene. Therefore, I hid those from the render (no glass / windows, just plain cabinet boxes). Rendering time decreased only slightly.
How can I improve both issues? And finally, how can I "pack" the .blend so it contains the materials as well - if I want to, say, share it here for debugging?