Best Practices
This page outlines best practices for gaining optimal performance with the Fast Sky skybox shader.
Use Cloud Detail Only When Necessary
Do not use cloud detail on dense clouds. The effect is barely noticeable as it only erodes cloud edges. Detail noise also performs faster on less dense clouds because it isn't sampled where there's no base cloud.
Use 2D Clouds if applicable
For straight, non-dynamic clouds or possibly, mobile platforms, enabling 2D clouds will significantly boost performance. If unsatisfied with fixed cloud shapes moving with the wind, enable detail noise to erode cloud edges. For more information, see Detail Noise
Use Fewer Cloud Layers
Try to limit the amount of cloud layers you use for your skybox
Use Fast Worley Alternatives
For better performance, use the faster Worley noise alternatives. The slower, more complex versions significantly impact performance, unless you are targeting high-end devices or dissatisfied with the artifacts.