Where are people having problems? Most people tend to set the graphics setting too high for their PC with some games and then moan about the low FPS. GTA IV has a calculator on screen in the options and it will tell you if the settings are too high for your system. What the game acknowledges as ok is actually and FPS between 20-30. The console versions only ran at 30fps and the PC Games only ran at 30fps with the Frame Limiter On (San Andreas ran at 25fps). So if your settings are too high and you have Frame Limiter turned on it will underclock the framerate to the nearest stable.