4 ms·

The actual question should be why isn't the UI faster and more responsive? Stating a solution as a requirement is rarely a good idea. We know that the iPhone a

by edderly 16y ago

The actual question should be why isn't the UI faster and more responsive? Stating a solution as a requirement is rarely a good idea. We know that the iPhone and Droid (and successor Droid X) has pretty similar hardware, both license the GPU IP block from Imagination Technologies. http://www.anandtech.com/show/3826/motorola-droid-x-thoroughly-reviewed/5 http://www.anandtech.com/show/3826/motorola-droid-x-thorough... However, we do have some details missing in comparison with the iPhone. For example, do we know whether Apple's UI is h/w accelerated? If it is, does the GPU have dedicated graphics memory (and how much?) or could a blitter be used? AFAIK, most if not all Android phones will have a GPU just simply as a function that Surfaceflinger (the Android window compositor) is an OpenGL implementation. It's only the emulator and during bring up that you'd use the software implementation of libagl/OpenGL. There's also a question that how good is a mobile SoC GPU at doing 2D. As mentioned, it isn't de rigueur that a mobile GPU has dedicated (fast) memory which is completely different in the PC space which has copious amounts. In the Droid X case you're weighing a 1GHz CPU vs 200Mhz GPU with a small number of cores. In fact, consider that we're fairly used to spending as much if not more for the GPU in desktop systems as the CPU. I do know for a fact that Imagination's 2D interface (PVR2D) has a large setup overhead which makes blitting of small bitmaps very slow, but somewhat ok with larger bitmaps. Add, alpha and it sucks in any case. You shouldn't also discount that perhaps the Android UI and app. framework is naively implemented compared to Apples.

newhouseb 16y ago
It's pretty straightforward to observe how iPhone's Safari is accelerated while Androids is not by using CSS 3D transforms. Google's original 2D layer (Skia) can only render affine transforms and not perspective transforms in webkit (largely because it just hasn't been configured in WebCore). Mobile Safari can in fact render perspective transforms indicating that it is using a different graphics engine than Skia (in fact Apple's documentation says that it is hardware accelerated). While this is only concerning the browser it allows for some benchmarks - try any transitions or 3D transforms in the browser and you'll find them much faster on the iPhone. Additionally Skia, which is used in Android's browser is used elsewhere in Android as well so its performance characteristics are more broadly relevant beyond just web browsing.

by edderly 16y ago

newhouseb 16y ago

It's pretty straightforward to observe how iPhone's Safari is accelerated while Androids is not by using CSS 3D transforms. Google's original 2D layer (Skia) can only render affine transforms and not perspective transforms in webkit (largely because it just hasn't been configured in WebCore). Mobile Safari can in fact render perspective transforms indicating that it is using a different graphics engine than Skia (in fact Apple's documentation says that it is hardware accelerated). While this is only concerning the browser it allows for some benchmarks - try any transitions or 3D transforms in the browser and you'll find them much faster on the iPhone. Additionally Skia, which is used in Android's browser is used elsewhere in Android as well so its performance characteristics are more broadly relevant beyond just web browsing.