No matter how fast your system or renderer of choice is, everyone is looking for faster renders. Why spend time waiting for projects to render when you can spend a bit of time optimizing for faster and cleaner renders. If you are using Arnold as a render engine (which is the same in all hosts) Arvid Schneider offers some great tips for optimizing Arnold.
There are really two streams for optimizing a rendering workflow. There is the IPR, or interactive preview render, while you are working. Then there is the final render. Optimizing Arnold for both will provide a much better experience as well as cleaner renders in the end.
There are certainly a lot of things to consider when optimizing Arnold (or any renderer). Scene dependant qualities will affect render times and render dependant attributes will affect the noise in the scene. Render attributes such as camera depth of field, motion blur, reflections, refractions, and indirect light all have to me optimized effectively.
Arvid steps through some of the relevant settings when optimizing Arnold for both IPR and final renders, with his new 2-part series.
