Sorry, but Yes, Input lag can occur at any FPS if the cpu or core that the input thread is running on is heavily (over)loaded
usually its the cpu getting overloaded in the case of noticeable input lag on a usb controller.
there are some causes of input lag that is caused by graphic configurations as well, such as a high MSAA setting (which will not visually impact the Dx9 plugin, but may cause performance and lag issues).
VsynC and Triplebuffering both have an impact on input lag for the worse, and the PreRender Frame setting in nvidia drivers also can directly affect the amount of delay between input and frame output.
usually its the cpu getting overloaded in the case of noticeable input lag on a usb controller.
there are some causes of input lag that is caused by graphic configurations as well, such as a high MSAA setting (which will not visually impact the Dx9 plugin, but may cause performance and lag issues).
VsynC and Triplebuffering both have an impact on input lag for the worse, and the PreRender Frame setting in nvidia drivers also can directly affect the amount of delay between input and frame output.