Smartphone users have for the first time surpassed tablet users in mobile data consumption. A study by Arieso reveals Apple’s iPhone 5 to be the “hungriest” in terms of download volume, with Samsung’s Galaxy S3 and HTC’s Sensation XL in second and third, respectively, and a phablet, the Galaxy Note 2, in a not-too-distant fourth.

And iPhone 5 users gobble up 50 percent more mobile data than 4S users and four times as much as iPhone 3G users, according to the study, which also notes the Galaxy S3 and the Note 2 upload the most data, putting the iPhone 5 in third.

Impressively, the study suggests the most extreme 1 percent of users on UMTS networks suck up nearly half of all downlink data. Data consumptions numbers are expected to keep rising across the board as more and more users gain access to LTE, particularly in favorable RF circumstances.

If tablets are bummed about taking second to smartphones in the mobile data eating contest, they can rest easy knowing that they are taking a big chunk out of the PC market share. A new Gartner study saw 90.3 million PC units shipped in Q4 2012, a significant 4.9 percent decline from Q4 2011. Gartner attributes the dip in numbers to tablets.

“Tablets have dramatically changed the device landscape for PCs, not so much by ‘cannibalizing’ PC sales, but by causing PC users to shift consumption to tablets rather than replacing older PCs,” according to the report.

The study reveals that HP held the top spot for Q4 2012, with more than 14 million units shipped, although it points out that number is less than what the company shipped in the same period from the previous year. Behind HP in Q4 2012 was Lenovo, with just less than 14 million units shipped, and Dell, in a distant third with a little more than 9 million.