big.LITTLE Processing

                       How long your mobile battery lasts??....10 Hrs..?...1 and half day??...2 days??....if itz more than 3 days then sure  that is gonna be a black and white mobile(basic model). So, it's basically how your mobile model extracts battery power efficiently and how long you keep your mobile active.

                       Mobile Computing is always been a thread connecting balancing performance and power consumption. There are several ways of processing which is considered to be good in different aspects and yield better efficiency. Of that, a challenging one but a reliable efficient processing technique is the BIG.LITTLE processing. It's powered by ARM processors for mobile devices like mobiles and laptops.
So by this technique it's a fact that you can charge your mobile battery for once and can use on a longer run than now.

                       Here what's the basic concept is a BIG CORTEX-A15 processor is paired with a LITTLE -CORTEX A7 processor. Why we are pairing these two processors?..Whats the benefit from this pairing?

Yeah, the answer is there is 70% power efficiency achieved by this technique. Cortex-A15 processor is distinguished as the High Performance achieving ARM processor while the Cortex-A7 processor is the most energy efficient ARM processor built till today. So think, wont be it's a very nice idea if tasks requiring large and complicated processings are done by the BIG one and the cheaper processing required tasks are handled by the LITLLE one. So the concept is that whenever a basic task is given CORTEX A7 processor handles it and when it reaches the peak of it's operating point a task migration is done to CORTEX A15 processor.

An important consideration of a big.LITTLE system is the time it takes to migrate a task between the  If it takes too long then it may become noticeable to the operating system and the system power may outweigh the benefit of task migration for some time.  Therefore, the Cortex-A15-Cortex-A7 system is designed to migrate in less than 20,000-cycles, or 20-microSeconds with processors operating at 1GHz.






So the hardware required for this pairing and a sophisticated sofware for assigning tasks and migrating the same for this pair are the two major challenges which has to be solved efficiently for a Power Efficient Mobile Computing.












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