Study by telecom network technology firm Arieso has found Apple's new iPhone 4S to consume on average twice as much data as the previous iPhone model and even more than iPad tablets due to increasing use of online services like the virtual personal assistant Siri. Data usage of the previous model, the iPhone 4, was only 1.6 times higher than the iPhone 3G, while iPad2 tablets consumed 2.5 times more data than the iPhone 3G, the study showed. The iPhone 4S is perceived by some as a data hog because of Siri, a well-reviewed virtual personal-assistant and search app. It is integrated into the iPhone 4S and responds to voice commands.