ARM redefines mobile power paradigm with A7 and big.LITTLE

Posted by Aharon Etengoff

ARM introduced its A7 MPCore processor this morning in San Francisco, California.

ARM exec Brian Jeff told TG Daily the A7 was "the most" energy-efficient application class processor the company has ever designed.

ARM redefines mobile power paradigm with A7 and big.LITTLEAccording to Jeff, the Cortex-A7 processor effectively builds on the low-power leadership established by the Cortex-A8 chip found in many of today’s most popular smartphones.  



Indeed, a single Cortex-A7 processor delivers 5x the energy-efficiency and is one fifth the size of the Cortex-A8 processor. Yet, it manages to provide significantly greater performance.



The 28nm Cortex-A7 processor - which occupies less than 0.5mm2 - is expected to facilitate the creation of sub-$100 entry level smartphones (2013-2014) that offer an equivalent level of processing performance to today’s $500 high-end smartphones.

In addition to the A7, ARM debuted its "Big.LITTLE" processing platform, which uses intelligent switching to enable higher-performance while extending battery life.



Essentially, Big.LITTLE pairs the high horsepower Cortex-A15 MPCore with the ultra-efficient Cortex-A7 processor - allowing mobile devices to automatically select the right processor for the right task based on performance requirements.

For example, the ‘LITTLE’, lowest-power processor - in this case, the Cortex-A7 - runs the Operating System (OS) and apps for basic always-on, always connected tasks, such as social media and audio playback.



The OS and apps can then be seamlessly migrated (within 20 microseconds) to the higher-performance processor as demands increase for high end tasks, such as navigation and gaming.

ARM engineer Peter Greenhalgh told TG Daily the hardware-based Big.LITTLE is OS agnostic, as it is completely transparent to the application software or middleware running on the processors.

Greenhalgh also noted that Big.LITTLE processing would initially be deployed on smartphones by various partners, but would likely find its way on to tablets at some point in the future.