ARM unveils Cortex A7 CPU and big.LITTLE Processing for high-end devices
By Pawel Piejko
October 20, 2011
UK-based chip manufacturer ARM has announced its most energy efficient CPU for portable electronics, called the Cortex A7, which will succeed the Cortex A8 CPU. The new arrival is designed to work as a stand-alone CPU in entry-level devices, and requires twenty percent the energy of its predecessor while offering twice the performance. High-end smartphones and tablets will also utilize the A7 as an additional source of computing power for less demanding tasks, with main processing provided by the upcoming ARM Cortex A15. Such a combination is dubbed big.LITTLE Processing.
ARM Cortex A7 - entry-level multi-core CPU
Built in 28nm process technology, the Cortex A7 is also five times smaller in size than the A8, occupying less than half a square millimeter. Typical clock speed for the A7 is 1.5GHz, while CPUs will be offered in single and multi-core varieties.
ARM outfitted the A7 CPU with the same lineup of features as its high-performance A15, including "virtualization, large Physical Address Extensions (LPAE) NEON advanced SIMD and AMBA 4 ACE coherency." The company hopes that by 2013-2014, Cortex A7 chips will find their way into sub-US$100 smartphones, delivering performance comparable to today's $500 high-end units.
Currently, the Cortex A8 is one of the most popular single-core chips on the market, used for instance in the Apple A4 and TI OMAP 3 SoC platforms.
ARM's big.LITTLE Processing
ARM's big.LITTLE Processing basically allows manufacturers to pair A7 and A15 ARM CPUs on a single platform. The A7 is responsible for less demanding background processing, while the A15 is used to deliver highest performance when required. Devices seamlessly select the right processor for the right task depending on the workload, thus extending battery life without compromising performance. big.LITTLE Processing is expected to offer up to 70 percent processor energy savings, compared to today's mainstream smartphones.
Last month NVIDIA unveiled a similar solution called vSMP architecture, revealing that its upcoming Kal-El Project quad-core system-on-a-chip includes a fifth companion core for less power-hungry tasks. Unlike big.LITTLE Processing, however, Kal-El utilizes ARM Cortex A9-based CPUs only.