We have a few tips that will help reducing render times. Give these settings a go and see how much faster you can get the software to render.
The first thing you can do with projects to speed them up is reduce the number of times a reflection can bounce from one shiny surface to another. By default C4D calculates reflective surfaces bouncing back and forth 5 times, this is overkill for most people. You can claw back some of your time by entering the render settings, going to the Options tab and reducing the ‘Reflection Depth’ setting from 5 to 1. If you notice the rendering looks different from before, try a value of 2 instead.
Global Illumination can really increase there render times in your render, but there are a couple of changes which will speed up your render quite a bit. Go to the Global Illumination tab and select the preset called ‘Interior – Preview (High Diffuse Depth)’ this will help a great deal. To speed things up even further, visit the Light Mapping tab at the top of the render settings window and enable ‘Build Radiosity Maps’. This will give you an extra kick of speed at the expense of higher memory usage. We can reuse global illumination cache files on you system it will cut down on the render times and will reduce the possibilities of light flickering throughout your frames.
If your project uses lots of slow blurry reflections and frosted glass, switch the render engine option at the top left of the render settings window from Standard to Physical. Then under the Physical tab set the Quality to Automatic. This will now do one of two things, either everything gets much slower, or much faster. It’s a shot in the dark but it’s worth giving it a go. If it all looks a bit grainy, you can play with the ‘Shading Error Threshold’ setting. Use values between 5% and 30%; lower values are cleaner but slower.
Reflection and transparency effects on your material, can increase the render times from few minutes to hours. It's extremely important that you run a few tests on your local workstation. For global illumination, test one frame with and without GI, sometimes the difference can only be a slight difference. You can also turn down some of the quality settings in the global illumination panel, test it out with screen shots and see if you notice any difference in quality versus how long it takes to render.
Object motion blur is weak and scene motion blur makes your renders take forever with all those samples. Think ahead if you can just add the blur in After Effects to one particular item. Render it separately or with an object buffer. Same goes with depth of field.