ARM Cortex A7: Not only is it better than the Cortex A8, but it also uses less power

ARM, the British semiconductor company that designs application processors and defines the instruction set that powers every mobile phone on the market, has just announced the Cortex A7. Before we dive into what makes that chip so special, let’s remind ourselves why ARM is a very unique company. It’s best to think of ARM like an architect. They design blueprints that they then sell to companies like Samsung, Texas Instruments, and Apple, who will then use those blueprints to build what’s called a system on chip. ARM creates the blueprints for many things, but they’re most known for their application processors, such as the ARM Cortex A9 that’s in Samsung’s Exynos 4210 and Apple’s A5, and their graphics processors, like the Mali 400 that’s in the Samsung Galaxy S II. ARM also licenses an instruction set, which you can think of as a recipe from a cookbook. Companies like Qualcomm and Marvel license the recipe, then they then tweak it to make it more unique to better suite their needs. This is obviously harder than simply buying an application processor, graphics processor, and slapping it on a piece of silicon.

On to the ARM Cortex A7, what makes it so kick ass? Compared to the Cortex A8, the A7 uses 5x less energy and is up to 1/5 the size, yet at the same time it’s faster in terms of performance. ARM says that by the time A7 based devices hit the market in 2013, they’ll be able to deliver the performance of today’s high end smartphones at price points as low as $100. Take a moment to let that sink in. Companies can build system on chips that have anywhere from 1 to 4 ARM Cortex A7 cores, and ARM expects that a majority of vendors will build a dual core solution.

All this sounds awesome, but there’s more. ARM’s fastest processor is called the ARM Cortex A15. It’s the first chip that’s roughly as fast as Intel’s low end portfolio. The problem with the A15 is that it consumes quite a bit of energy. It’s still incredibly power efficient compared to said Intel parts, but ARM thinks they can do better, so they’ve introduced something called a “big.LITTLE configuration”. In plain English, it’s ARM’s name for a processor that has both ARM Cortex A15 cores and A7 cores. When your smartphone or tablet needs the extra horsepower, it’ll use the more powerful A15 cores. When your device is just idling, it’ll switch to the low power A7 cores.

If this sounds familiar then you probably remember our article about how NVIDIA snuck a 5th core into their quad core processor that’s due to launch next year. NVIDIA’s Tegra 3 will have 4 high speed Cortex A9 cores that can scale up to 1.5 GHz and a 5th core that’s capped to 500 MHz. When you don’t need the horsepower, your device will switch to that ultra power efficient slower processor.

As always, if these type of articles interest you, then we highly recommend you head over to Anandtech. They break down the A7 announcement with far more detail, perfect for chip geeks.

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