Slim and sleek as it is, the iPhone is really the Hummer of cellphones.

It’s a data guzzler. Owners use them like minicomputers, which they are, and use them a lot. Not only do iPhone owners download applications, stream music and videos and browse the Web at higher rates than the average smartphone user, but the average iPhone owner can also use 10 times the network capacity used by the average smartphone user.

“They don’t even realize how much data they’re using,” said Gene Munster, a senior securities analyst with Piper Jaffray.

The result is dropped calls, spotty service, delayed text and voice messages and glacial download speeds as AT&T’s cellular network strains to meet the demand. Another result is outraged customers.

Cellphone owners using other carriers may gloat now, but the problems of AT&T and the iPhone portend their future. Other networks could be stressed as well as more sophisticated phones encouraging such intense use become popular, analysts say.