Samsung's Exynos 5 Octa, the chip which powers the international version of the Galaxy S 4 and a few other upcoming Samsung products, has eight ARM CPU cores. Four of these are based on the high-end Cortex A15 architecture and are used for more intensive tasks, while the other four are based on the slower but more power-efficient Cortex A7 architecture. These cores work together using an ARM-developed feature called big.LITTLE.
Up until now, only four of those eight cores could be used at one time, but Samsung announced today that this would change later this year: starting in the fourth quarter of 2013, Exynos 5 Octa systems-on-chips (SoCs) will be able to use all eight CPU cores at once. All four A15 cores and all four A7 cores will be able to execute code at the same time, which the announcement says will "enable Samsung to achieve efficiency and high-performance."
This capability isn't exclusive to Samsung's chips—it's actually a variant of big.LITTLE called big.LITTLE MP, and it's specified in ARM's big.LITTLE whitepaper (PDF). Engadget points out that MediaTek's MT8135, a quad-core implementation of big.LITTLE with two Cortex A15 cores and two Cortex A7 cores, will also use big.LITTLE MP when it is released.
Based on what we know about big.LITTLE, it should theoretically be possible to change a standard big.LITTLE setup to a big.LITTLE MP configuration in software via an update. Samsung's press release doesn't make this clear, however—it may be the case that devices based on the older Exynos 5410 (the Octa that ships in the Galaxy S 4) will be left alone, and big.LITTLE MP support will only be implemented in the more powerful Exynos 5420 that is scheduled to begin showing up in devices this fall. In any case, it's nice to see that Samsung's eight-core SoC will soon be able to use all eight of its cores at once rather than being a functionally quad-core SoC as it is now.