Better scrolling

I have jpegs, dynamic text, sometimes vectorel data in scrollers container.

what are the factors effecting the smoothness of contet scrolling?

1- Frame rate ?
2- Type of an embedded image file (jpeg, png, gif, bmp etc.)?
3- Size of the content to scroll?
4- Amount of easing?
5- other properties of the image like autosmoothing on/off…

etc… etc…

I am hoping to get closer to the more smooth, less flicking scrolling experience…

thx