CHIP DESIGN OUTFIT ARM has announced its Cortex A7 to address energy efficiency with the "Big.little" processor approach.
The Cortex A7 chip offers five times the energy efficiency compared to the ARM Cortex A8 processor and is one-fifth the size. The chip is specifically designed for smartphones and will enable a sub $100 smartphone in 2013 to have the performance level of a $500 smartphone of today.
At a briefing in central London yesterday, Tom Cronk, deputy general manager of the processor division at ARM said, "It is the latest processor in our applications processor range. It has been developed, without compromise, for really moving the bounds of what's achievable in terms of energy efficiency."
The multi-core Cortex A7 will be fabbed at the 28nm process node with resulting surface area of 0.45mm^2. ARM said the chip will be fully backwards compatible and available in both single and dual-core versions.
ARM also introduced its "Big.little" processor concept with the Cortex A7. The idea here is to have two processors inside a mobile device like a smartphone. The example given was a Cortex A7 coupled with a Cortex A15 so you have energy efficiency but also performance.
With two processors in place, the right one can be used for the right job. The Cortex A7 will be used for "always on and always connected tasks" such as phone calls and text messages, whilst the larger Cortex A15 will deal with more demanding tasks such as videos and gaming.
According to ARM this can yield up to 70 per cent energy savings on common workloads compared to a current high end smartphone and will therefore increase battery life. What's also important is that the operating system and apps software knows nothing of the processor switching so it doesn't get in the way. µ