Global Illumination can bring any system to it's knees if the settings are inappropriatly set. Here are the things I check before hitting the render button: - Use bump maps only on objects close to the camera. Bump maps, especially complex or noisy ones can increase render times by 10. - Set maximum ray depth to 4 unless there is transparency that requires more. - Use as few extra lights as possible. If you need extra lights, use spots instead of bulbs. Realize that soft shadows with spots will increase render times. - Be careful about increasing photon counts in GI. Usually simply selecting "Good" instead of "Fast" for shadow quality will provide acceptable results. Otherwise, you can choose Excellent. If you get goofy shadows, try rendering with Interpolation off. This will increase render time though. There are all sorts of other little things but these are the most significant. Good Luck! Mark