The upcoming iPhones, which will be unveiled tomorrow (September 12th), will be equipped with new processors from Apple, the A11 models, that apparently will be more powerful and more energy efficient.
The muscle power will be supplied by the two “Monsoon” cores, which will handle the resources-hungry apps and services, while the four “Mistral” cores will handle the less hungry apps, while reducing the power consumption of the new A11 chips.
Just to clarify on the A11: it's two high-power Monsoon cores and four low-power Mistral cores, all independently addressable. No Fusion
— Steve T-S (@stroughtonsmith) September 10, 2017
Of course, it’s not like the end users will have to do anything about it, but it’s helpful for developers. Also, the new A11 chips should make sure that apps are running smoothly while the battery life should be increased. And iPhone users know that battery life is the the biggest issue they had from the very beginning.