Hello everyone, I just got finished trying two different build settings on a iPhone 4 (native which took about 45ms GPU time per frame which my scene, and 320p, which took about 9ms GPU time per frame).
Having seen that, how is it possible to run anything (no matter how simple) on a iPhone 4 at native resolution with a good frame rate? Since no matter how simple your scene is, the phone still has to render all of the pixels? Is it even realistic to use native resolution on any type of game / application that depends on a good frame rate?
Yes, use simple/fast shaders and no dynamic lighting, and little or no overdraw.
iPhone 4 (and it’s cousin the iPod Touch 4) was always the worst iOS device for us because of the mismatched GPU and screen. It is possible to run 3D games at native res on those devices, but it requires really aggressively simplified shaders and a minimum of overdraw. In practice that’s hard to do, especially using a stock solution like Unity, so most games, even ones with custom engines, render the main scene at less than retina res and then render the UI overtop at retina res so that it feels crisp. Also, MSAA on iOS PVR hardware is pretty affordable (5-10% perf penalty) so you can turn that on to get a better looking, sub-native res image.