As many as seven editions of the Apple iPhone have been launched since the introduction of the first iPhone in 2007 by Steve Jobs.
Every new iPhone has witnessed innovative features and hardware improvements such as better multitouch screen, faster processor and a more responsive touch interface.
A recent YouTube video demonstrates the performance of all seven generations of iPhones (from the original iPhone through the iPhone 5s).
The video, courtesy of YouTube user, EverythingApplePro, makes a speed test comparison of the various iPhones.
The phones are subjected to various tests such as the time taken to boot up or shut down, web browser launch time, time taken to open a web page and so on.
Check out the demo video depicting the performance of iPhones from the original iPhone through iPhone 5s in the speed test comparison below:
As iPhone Hacks reports, all iPhones performed top notch while running their native OS, but with advanced improvements in subsequent iOS iterations, the iPhones are consuming more memory and processing resources.
This is reportedly the reason why several iPhone generations from the iPhone to iPhone 4 had similar performance stats, as depicted in the graphic charts (see below) which were revealed by Apple during the iPhone 5s launch keynote presentation.