Take all 8 released versions of the Apple iPhone, a large number of hands, and you have a test to determine how fast each generation's processing capability is compared with other models; the Apple iPhone 3GS was actually the first to shut down and you might notice that the iOS 7 models all shut down at the exact same time. Interesting...Source: http://www.phonearena.com/news/Watch-all-8-Apple-iPhone-models-battle-each-other-in-a-test-of-speed_id47817
