iOS bitmap scrolling quite sluggish


Part of our App, we have some vertical scrollable content (credit, legal, etc) mostly texts and some are bitmaps.

For some reason, the scrolling on the iPad and iPhone 4 is rather slow and sluggish, and always feels a bit behind your scrolling finger…
(Ironically, on the iPhone 3Gs its a bit better due to its lower screen resolution (and despite of its slower older cpu/gpu ).

Is there a way to optimize such non-demanding and rather trivial UI behavior?
This is especially noticeable because the main App functionality in 3D is extremely responsive and smooth…leaving these UI screens to stick out…


If something is slugish on 4th gen & iPad1 but runs well on 3GS, thats nearly always a clear indication of fillrate overusage.
The problem then is not about it moving smooth or alike but as a matter of fact the gpu can’t render as many pixels as it would need to fullfill your rendering desires.

Reason for that is usage of inappropriate (mobile unfriendly) shaders which use blending, alpha blending or at worst transparent cutout shaders.

Look at what shaders you use and ensure to not use blending of any type unless you really need it.