The results of the GPU test show that the newer iteration of the Apple iPhone is 7 times faster than the older model when it comes to running graphics. The Apple iPhone 4S scored 73.1 vs. 11.2 for the Apple iPhone 4. Another GPU test resulted in a score of 122.7 for the former against 15.3 for the latter. While the Apple iPhone 4S trailed the GPU test score of the Apple iPad 2, it beat out results from other handsets that come with higher clocked CPU's like the Samsung Galaxy S II, the Samsung Infuse 4G and the Motorola DROID BIONIC.
While Apple lowered the clock speed of the A5 found in the iPhone 4S as opposed to the 1GHz speed on the iPad 2, the result was a small drop in performance versus a big jump in the life of the battery.
source: AnandTech via AppleInsider