ARM has just announced the Cortex A7, a small CPU core that is only 1/5 of the size of the popular Cortex A8 which was used in countless smartphone system on a chip (SoC). ARM says that its Cortex A7 processor provides better performance and uses less power when compared to the A8. Today, most phones are powered by one or more Cortex A9, and in the future, some designs will start using ARM’s A15 core.
The A7 has been built to be used as a companion core, which means that it will be paired with one or more high-performance processors, and when the workload is low, the A7 kicks in to take over the task. If something intensive happens, the faster cores will do the heavy lifting.
This will allow the next-gen products to be more power efficient as the appropriate power and silicon resources will be applied to any given tasks. Interesting, this is also a concept that is being used by the upcoming NVIDIA Tegra 3 chip that features 5 Cortex A9 core, with one that has been tweaked for low-power, low frequency usage.
Somehow, it seems that “companion cores” are the immediate future for low-power / high-performance chips. ARM says that in theory, the A7 could save up to 70% in terms of power consumption.