If you wish to play with a variable frame rate instead of a locked 60 or 30, then you will need to leave iFPSClamp set to 0. You can also set iFPSClamp to 30 if you plan to cap your frame rate to 30fps with something like RTSS or DXTORY.
Mcgeehe: // Your PC will need to be able to maintain 60fps or the entire engine slows down when doing this.
