Question about setFrameRateLimit

[Zhiren]

I am writing a game and set the frame rate limit to 60 FPS.  However the frames actually run at about 30 FPS.  So I just am curious why that is. If I set the Vsync on and turn off the limit, it runs at 60. Would this change from computer to computer with different refresh rates?  Also, I probably shouldn't be putting timed events based on a frame count should I?  I probably should use the built in Time functions, right?

[Ixrec]

Would this change from computer to computer with different refresh rates?

Yes.  Also different processor speeds and OS scheduling behavior.

Also, I probably shouldn't be putting timed events based on a frame count should I?  I probably should use the built in Time functions, right?

Yes.  A frame is not a unit of time.

[Nexus]

Game logic should not depend on the actual time passed in a frame, otherwise you get non-deterministic and non-reproducible behavior. The typical approach is to let the logic run at a constant rate independent of the frame rate, and adapt the graphics dynamically. Fix your timestep is a more sophisticated article on that topic, there have also been several forum discussions in the past.