On the surface, it would appear Apple is behind the times with the A6 processor powering the iPhone 5. The 1.02GHz dual-core A6 (ARMv7) processor is slower in terms of clock speed, and many Android phones are already shipping with 1.5GHz chips. 1GB of RAM is included in the iPhone 5, which is half of what many flagship Android phones possess. But here's the thing: Apple is vertically integrated and they can hand-tuned their SoC architecture and OS to take excellent advantage of each other. You will not find a more optimized CPU/OS pair in the market today, than the A6 and iOS 6.
Android phones use an OS from Google and a processor from any number of companies. They work together, but there are inefficiencies that Apple can more efficiently deal with. In other words, Apple makes the absolute most of its SoC. Apple can squeeze every drop of performance out of it, and also design future SoCs to better alleviate what Apple considers bottlenecks in iOS. You could also argue that the A6's lower clock speeds help when it comes to battery life.
The simple fact of the matter is that the iPhone 5 is much faster than the iPhone 4 and 4S. In average use, browsing the web and flipping through the usual complement of apps, the speed increase feels about like that between the iPhone 4 and iPhone 4S. Page flips are slightly quicker, apps load slightly faster. But there's additional graphical horsepower in here too, so games that are updated to make use of the extra pixels won't see any slowdowns.
Web browsing on the iPhone 5 is very quick. And our SunSpider test rings up at a staggering score of 941ms, which is over twice as fast as the iPhone 4S (which sported scores of around 2,200 in our testing) and even quicker than two of the newest Android rivals: the Galaxy S III and HTC One X, which ranged between ~1,600 and 1,800.
The other browser-based benchmark we ran was Browsermark, which netted a score of 182435. That smokes the 108304 score from the Galaxy S III: and even on the tablet side, it beats out the Eee Pad Transformer Prime TF201 (106275) and the Galaxy Tab 10.1 (89673). We also ran our iPhone 4S through Browsermark, and it scored 103286.
GLBenchmark specifically focuses on the graphics performance of the graphics core in a given mobile test device. This benchmark measures OpenGL graphics performance across a number of rendering workloads. "The benchmark contains high-level 3D animations and low-level graphic measurements. GLBenchmark Egypt HD is the upgraded version of the old Egypt 2.1 test: it is more complex, uses more and higher resolution textures and is optimized for 1080p."
Make no mistake: the iPhone 5 is no marginal improvement over the iPhone 4S in terms of raw speed. It more than doubles the speed in practically every test we threw at it, and it will surely show off its muscle as more and more apps are built to take advantage of the extra oomph provided by the A6 and its healthier allotment of 1GB of system RAM. Beyond elegant functional and mechanical design, the new Apple A6 processor clearly demonstrates Apple's design prowess when it comes to base silicon technologies as well.