Although NX/Simcenter can use the Tools --> Movie function, to create an AVI movie in the Post Processor, the Post Processing Animation function dialog, in Advanced Simulation in NX 9.0 - 10.0 and Simcenter 11.0 - 12.0, has a toolbar icon on the Animation dialog to create an animated GIF.
The following solution provides the steps to change the speed of the generated GIF file.
In the Animation dialog, if the Animate dropdown is set to result, the number of frames affects the smoothness and speed of the animation in the GIF file. The Frame Delay time makes no difference in the speed. If a large number if frames are are selected, the size of the GIF file can be quite large.
If the Animation is set to Iterations, for dynamic models, the number of animation frames is limited by the user Interface. The number of frames is controlled by the increment set by the Start and End Iteration fields and the Step Size. A step size of 1, animates each time step or increment. Increasing the Step Size will reduce the number of animation frames and is displayed on the Animation dialog for reference. A step of 3 will animate every third time step or increment