ARM boosts energy efficiency with Cortex A7 processor

UK success story ARM has unveiled what it claims to be its most energy-efficient processor design to date, the Cortex A7, and announced the big.Little processing model for future chips designed to boost performance.

The new A7 chip offers five times the energy efficiency of the firm's A8 processor and is a fifth of the size. The chip is specifically designed for smartphones and will enable sub-$100 smartphones in 2013 to have the performance level of a $500 smartphone of today, said ARM.

At a London launch event, deputy general manager of ARM's processor division, Tom Cronk, introduced the A7 as the latest in the firm's applications processor range.

"It has been developed, without compromise, for really moving the bounds of what's achievable in terms of energy efficiency," he added.

The multi-core processor core A7 will be delivered using the 28nm process with a resulting surface area of 0.45mm2. ARM said the chip will be fully backwards compatible and available in single- and dual-core versions.

ARM also introduced its big.Little processing concept. The idea here is to pair up two processors inside a single mobile device – for example, the A7 and the A15 – in order to meet both performance and energy efficiency demands.

With two processors in place, the right one can be used for the right job, explained ARM. The A7 could therefore be used for "always on and always connected tasks" such as phone calls and text messages, while the A15 could be tasked with more demanding operations such as videos and gaming.

The software and apps know nothing of the processor switching so it doesn't get in the way, the firm explained.

This setup gives up to a 70 per cent energy saving on common workloads compared with current high-end smartphones and will therefore extend battery life, according to ARM.