Though most of us out here at iphonefootprint are not going to upgrade to iPhone 3G S when it is launched, partly for the hefty upgrade price we need to pay and for the ignorable features it offers, it still is  worth to let you know the differences between the iPhone 3G and the new iPhone 3G S.

We would be getting most of the features that the iPhone 3G S sports except the extra speed, digital compass, voice control and video recording feature.

Here is a little difference, though that might be of concern to iPhone app developers.

The difference is between the graphics processors of the two iPhones. The 3G S is powered by PowerVR SGX that supports hardware acceleration of OpenGL ES 1.1 and OpenGL 2.0 while the iPhone 3G is powered by PowerVR MBX, which supports only OpenGL ES 1.1.

OpenGL ES 1.1 is commonly used in most handheld devices, 2.0 is not that very widely used till now. However, the 2.0 version has the capability to support more complex games and applications. The two versions are basically incompatible with each other. The rule of the thumb here is that applications developed specifically for the 2.0 version won’t be that good on a device that runs on 1.1.

Now, what does this remind you of? The App Store already has applications that are specific for the iPhone, which are not compatible on the iPod touch. Some of the apps are like those apps which requires the camera on the phone or call generating applications.

With the release of the iPhone 3G S, there is a possibility of further segregating the applications into three groups based on compatibility. Those of us who have decided to stay on with the 3G iPhone would probably be unable to use applications meant to work with the digital compass, video camera, voice memo or those app that requires higher speed.

Hmm, more incompatibility issue could surface as we move on. We have to wait and see.