This problem is not mine, so I will need some time to provide details.
XY sets up the Java environment for Slick2d programming based on a tutorial video series. XY uses same code as the tutor, but tutor gets 800 FPS and XY gets 5. The application is working as it is supposed to, but it has a major FPS issue. XY uses Eclipse for compiling.
What is worth checking in such a situation?