[Galaxy S 4 General] D™:
what samsung said:

Since Samsung announced the Exynos 5 Octa at CES 2013, one major criticism has been leveled at its implementation of big.Little technology time and again: for some reason, it has only ever been able to run 4 of its 8 cores at a time. Not only that, but it has never been able to mix-and-match the higher performance A15 cores with power efficient A7 cores to get the best possible configuration for performance and power usage. Effectively, the Exynos 5 Octa acted like a quad core processor with the ability to toggle between two different architectures. That situation will be changing shortly as Samsung prepares to launch Heterogeneous Multi-Processing (HMP) for the Octa in Q4, making it possible to run any number of cores in any configuration.

In the original architecture, processor intensive applications would force everything to run on the A15 cores. For example, playing a game often resulted in the super-charged cores running simple background processes like those for handling phone calls and text messages. The updated architecture is designed to direct threads with higher priority and computational demands towards the "big" Cortex-A15 cores while low priority and less demanding threads can be run on the "Little" Cortex-A7 cores.

While I advise against it, you can take a look at Samsung's promotional video that demonstrates how the big.Little architecture works under Heterogeneous Multi-Processing.

Availability for Samsung's processor customers is scheduled for a 4th quarter release. Since HMP appears to be a combination of hardware and software, existing and immediately upcoming products, like the just-announced Galaxy Note 3, probably won't be able to take advantage of it. However, this definitely gives us something to look forward to as Samsung prepares to launch new flagship devices in the coming months.

In a view of kitkat 4.4, it might be possible with S4 too, but Samsung is quite over S4.

What Meizu said:

Meizu Says Existing Samsung Exynos Chips Can Be Upgraded To HMP 'True 8-Core' Via Software, New Hardware Not Needed After All

Earlier this week, Samsung announced that it was bringing Heterogeneous Multi-Processing (HMP) to Exynos 5 Octa chips. Samsung didn't clarify if HMP would require new hardware, but that was the implication. Now Meizu has unexpectedly announced the Exynos 5 Octa chip in its recently unveiled MX3 will be getting HMP through a software update.

cores. That means either the four high-power A15s are active, or the four low-power A7s are cranking away. There was no way to mix the active cores from the two CPU islands. To make matters worse, Samsung's implementation of cluster migration was broken by a cache bug. Switching between CPU islands caused the cache to be flushed from memory. Moving to HMP should fix that problem by allowing the system to assign tasks dynamically to both A7 and A15 cores. All eight cores could even be running at the same time.

Meizu is one of the few OEMs buying Exynos chips from Samsung and has a close relationship with the South Korean company. Presumably it has the inside scoop from Samsung on what its chips are capable of. This opens the door for HMP upgrades on other Exynos 5 Octa devices.

If what Meizu said, get possible, then we may get it for S4. So wait till Kitkat release.:angel: