Apple’s iOS 5 is already powering 33% of all eligible iOS devices, though it’s only been available for a week, according to new data from the Localytics research group (

If you remove the newly launched iPhone 4S (which ships with iOS 5), that number drops a tiny bit, but still remains at 31%. Looking at devices, the iPad 2 and iPhone 4are leading the charge, with 36% and 35% iOS 5, respectively. Original iPads clock in with 33% iOS 5 proliferation, followed by the iPhone 3GS (27%), the third generation iPod touch (23%), and the fourth generation iPod touch (17%).

In order to determine this, Localytics analyzed all iOS device usage from iOS 5’s Oct. 12 release date through Oct. 17. Localytics is a Boston-based software company offering an app analytics platform.