[After Effects]-Turbulent Noise/Fractal Noise

Difference between Turbulent Noise(from CS4) and Fractal Noise

I found Turbulent Noise as new feature in CS4 and wondered how this differ from Fractal Noise.

here is my simple summarize...

Turbulent Noise-faster to calculate, can't create cycle animation
Fractal Noise-slower to calculate than Turbulent Noise, can create cycle animation