The first SimplyTest is using Safari to load the same page. Both iPhones are running iOS6, Apple's latest and arguably fastest mobile operating system. Both iPhones connected to the same fast wi-fi network.
Although non of these tests are scientific, you can see the difference is loading speeds. Worth noting that it looks initially like the iPhone 4 (Black) appears to load faster, its just because the page was used perviously used, Safari then reloads the page.
From a standing start, the difference is loading times is clear. The A6 chip in the iPhone 5 (White) is I would estimate about twice as fast, the A6 employees a dual core CPU against the iphone 4's single CPU.
The Simplytwitter test is the most telling as I would say the difference between the two iPhone's is around 5-6 seconds, #Fast! Its not until you compare the 4 and 5 together that you notice the difference and the waiting to tweet.
I would be interested to here your thoughts, are your experiences the same?
I can be found on twitter @SimplyApple_