How long does it take to switch a UIImageview image for each version of the iPhone on average?
I'm trying to get metering enabled on an AVAudioPlayer and I want to know how often I chould check metering levels so that the image displaying the metering doesn't lag behind actual playback.
How long it takes to set the image is unpredictable. It also depends on where you are loading the image from, and wether it has been loaded before. [UIImage imageNamed:...] already does some optimisation when you are reusing the same image, but that doesn't mean you get predictable speed.
If you want to do something like displaying a level meter, you might be better off doing the drawing yourself in a custom view. Override drawRect: and draw the status of the levels in your 'level' view. Us a level property and override it's setter to call setNeedsDisplay if the property value has changed.