It will have a die size of less than 0.5 square millimeters and draw less than 500 milliwatts of power, according to Nandan Nayampally, director of marketing for the ARM processor division.

Other chips, such as Intel's Core i7 laptop processors, ramp down the clock speed or disable cores to reduce power consumption. But there's a limit to how much power can be saved using that technique, said Nathan Brookwood, principal analyst at Insight64.

"There's a dynamic range for which you have to optimize the processor design, and there's a limit to how much you can power it down and still have it run at all. That's why Intel had to go off and design the Atom processor very differently from the i3, i5 and i7 series," he said.

ARM's approach has "a lot of promise," Brookwood said, "especially for devices where battery life is important, and where you're running applications with very different power requirements."

The A7 and the A15 will have "identical" feature sets, so software applications will run on both cores without modification. ARM designed a policy manager to determine on which core the application should run.